Attackers are using compromised websites to present fake Cloudflare verification pages that steer Windows and macOS users toward executing malicious commands. The findings establish a delivery attempt, not a confirmed infection or identified malware family. The activity exploits the familiarity of browser security checks. Instead of completing a legitimate verification, visitors receive instructions intended to […]
Microsoft has released an emergency Windows update to remove trust in certificates associated with compromised eMudhra certificate authority keys. The out-of-band update, issued on October 26, 2026, eliminates seven certificates from the Windows trust list. Following this, the same removals were applied to Microsoft Edge on October 27, as stated by the Microsoft Security Response […]
Attackers are compromising camera management software to gain remote access, run malicious DLLs through a legitimate Windows component, and maintain persistent footholds in enterprise environments. The incidents show how overlooked surveillance applications can become entry points into broader corporate networks. Huntress observed several intrusions during September and October involving CMS.exe, a camera management application installed […]
A previously undocumented Sirius backdoor variant during a priority customer investigation, revealing a multistage campaign that hides malicious code inside legitimate Windows processes. The supplied analysis details stealthy remote access and persistence, although it does not establish specific password extraction capabilities. The financial urgency and regional tailoring reflect established phishing techniques that exploit trust in […]
Just finished the Checkpoint machine on Hack The Box (Medium difficulty) and it was a really enjoyable Active Directory box with some modern and creative attack paths.
I started with the provided credentials for `alex.turner`. After some enumeration I discovered that a previously deleted account (`mark.davies`) could be restored and that this account had write access to a share called DevDrop. This share was used by the organisation to stage VS Code extensions.
By creating a malicious VSIX extension targeting VS Code engine version 1.118.0 and dropping it on the share, a scheduled task automatically installed the extension and gave me a reverse shell as `ryan.brooks`. This was a really clean example of abusing enterprise software deployment processes.
From the `ryan.brooks` foothold I used Rubeus to obtain a TGT, then leveraged bloodyAD to create a malicious dMSA under a writable OU and impersonated a higher-privileged account. This eventually granted access to a VMBackups share containing a Windows Server memory dump. Using Volatility I extracted the local Administrator NTLM hash from the dump, authenticated with Evil-WinRM, and captured the root flag.
Overall, Checkpoint does a great job of chaining together several current techniques: writable shares for extension abuse, deleted object restoration, dMSA abuse, and memory forensics. It’s a solid Medium box that feels realistic and rewards careful enumeration.
Would recommend it to anyone working on modern Windows / Active Directory attack paths.
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
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.
BRONZE SANDCASTLE intrusions involving hidden Windows backdoors and the theft of the Active Directory database. The suspected China-based group combines legitimate applications, malicious DLLs, and encrypted payloads to execute code inside trusted processes while limiting artifacts available to conventional file scanning. Investigations covering August 2025 through August 2026 identified victims in the Philippines, Taiwan, Afghanistan, […]
KGB RAT, a Windows remote access trojan marketed as legitimate administration software, combines surveillance, credential theft, and configurable malicious functions with a built-in crypter advertised to evade Windows Defender. Researchers identified unobfuscated payloads, obfuscated variants, and encrypted loaders that reconstruct malware during execution. This distinction matters: the crypter conceals the underlying payload, while the deployed […]
Google has awarded XBOW $250,000 for creating an AI-assisted exploit chain that enabled code execution outside the Chrome browser’s renderer sandbox on Windows. This reward marks the first full-chain payout for Chrome under Google’s vulnerability reward program, introduced in April 2026. According to XBOW, all three vulnerabilities involved have since been fixed. Google Pays $250,000 […]
Three Windows BitLocker vulnerabilities, as described in the provided advisory, could let attackers elevate privileges or bypass security protections under various access conditions. Microsoft is the assigning authority, with a release date of October 13, 2026, and all three vulnerabilities are rated Important. Two require existing local privileges, while the third requires physical access. We […]
Microsoft has addressed a vulnerability in Windows Shell that attackers are actively exploiting, allowing them to bypass the Mark of the Web (MOTW) security protections. Designated CVE-2026-96951, the flaw was disclosed on October 13, 2026, during the company’s monthly security update. Microsoft classifies the vulnerability as Important, giving it a CVSS v3.1 base score of […]
FortiGuard found SectopRAT hidden in modified audio software files, using staged loading to steal browser data and remotely control infected Windows PCs.
Varonis Threat Labs discovered AvisLoader, a Windows malware loader that uses the Tox peer-to-peer network for C2 and arrives through a malicious ClickFix lure.
Blackpoint Cyber found ChainScript, a Node.js RAT spread through fake Spotify, Zoom and Teams installers that uses Polygon smart contracts to locate its C2 server.
Login
