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A ransomware actor abused the legitimate mhyprot2.sys anti-cheat driver from the game Genshin Impact to terminate antivirus and endpoint protection processes before encrypting systems. Trend Micro reported that the attacker dropped and installed the signed driver, then used it to kill security tools by exploiting the driver's kernel-level privileges, allowing the intrusion to proceed with reduced detection and resistance.
The technique highlights a bring-your-own-vulnerable-driver style tradecraft in which trusted or signed drivers are repurposed to bypass defenses and gain powerful access on Windows endpoints. By weaponizing a legitimate game anti-cheat component rather than custom malware alone, the actor was able to undermine security products and improve the chances of successful ransomware deployment, underscoring the need for driver blocklists, application control, and monitoring for unexpected driver installation on enterprise systems.
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2 events from the most recent confirmed update back to the earliest known activity.
Trend Micro published research describing a ransomware actor abusing the Genshin Impact anti-cheat driver to terminate antivirus processes. The report publicly documented the technique and its use in real-world attacks.
A researcher analyzed a ransomware campaign using the legitimate mhyprot2.sys gaming driver to terminate security processes and linked its ransom note TOX ID to Rever ransomware. The analysis also identified associated AVG.MSI, AVG.exe, HelpPane.exe, svchost.exe, and logon.bat artifacts and recovered the batch script and ransom note through sandbox execution.
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Ransomware operators have been observed using **bring-your-own-vulnerable-driver (BYOVD)** techniques and custom anti-security tools to shut down endpoint protections before encrypting enterprise networks. Kaspersky documented a MedusaLocker intrusion in Brazil in which attackers accessed an SMTP server over RDP with valid administrative credentials, used **Mimikatz** to extract NTLM hashes, and moved laterally with pass-the-hash via PowerShell-based WMI and SMB execution before deploying a new AV-killer tool, `All.exe`. That tool loaded a renamed **TechPowerUp `ThrottleStop.sys`** driver (`ThrottleBlood.sys`), exploited vulnerable IOCTLs for physical memory read/write, hijacked kernel execution through `NtAddAtom`, and repeatedly terminated products from Microsoft Defender, CrowdStrike, SentinelOne, Sophos, Symantec, Bitdefender, ESET, Avast, AVG, McAfee, Panda, Quick Heal, and Kaspersky; the driver issue was assigned **`CVE-2025-7771`**. A separate report on **The Gentlemen** ransomware described a similar pattern in enterprise attacks across the Asia-Pacific region, where the group likely gained entry through an exposed FortiGate device or stolen credentials, then conducted Active Directory reconnaissance, used **PsExec** for lateral movement, established persistence with **AnyDesk**, abused **GPO** and **NETLOGON** for domain-wide deployment, and exfiltrated data with **WinSCP** for double extortion. TrendAI said the group evolved from generic anti-AV tooling to customized variants tailored to the security products installed in each victim environment, while also disabling Windows Defender and recovery mechanisms before dropping `README-GENTLEMEN.txt` and encrypting files with the `.7mtzhh` extension. Together, the incidents show ransomware crews increasingly pairing credential abuse and lateral movement with vulnerable-driver abuse and bespoke defense evasion to maximize encryption success.
Aug 21, 2026
Researchers and incident responders reported continued abuse of **Bring Your Own Vulnerable Driver (BYOVD)** techniques to disable endpoint protections, including **CrowdStrike Falcon**, by loading legitimately signed but flawed Windows kernel drivers. One newly analyzed zero-day driver family included more than 15 variants with valid Microsoft signatures and an IOCTL path such as `0x22E010` that accepted a process ID and invoked `ZwOpenProcess` and `ZwTerminateProcess` from kernel mode, allowing attackers to kill protected security processes without alerts. A proof-of-concept dubbed **PoisonKiller** demonstrated successful termination of the CrowdStrike EDR process through the driver’s symbolic link, underscoring the risk created by trusted but unrevoked third-party drivers. Separate reporting from Sophos and industry coverage tied the same broader tactic to real intrusions and ransomware activity, including ongoing abuse of **Terminator** and related tools built around vulnerable **Zemana** drivers. Attackers used IOCTL flaws to place their own processes on allow lists and then terminate AV and EDR components, while some incidents showed operators switching to alternatives such as **AuKill** when initial attempts failed. Defenders were urged to combine tamper protection, strict privilege controls, patching, and aggressive blocklisting of unnecessary vulnerable drivers, as signed-driver abuse has spread from advanced actors to commodity ransomware crews and lower-tier criminals.
Jun 30, 2026
Fortinet/FortiGuard Labs reported that the **Interlock** ransomware group—described as a smaller, non-**RaaS** operation—ran a months-long intrusion campaign primarily targeting the **education sector** in the US and UK. Initial access was observed via **MintLoader**, including “ClickFix” social-engineering lures, followed by post-compromise activity using a JavaScript implant referred to as **NodeSnakeRAT**, lateral movement with valid accounts and living-off-the-land techniques, and broad discovery prior to impact. The operation follows a **double-extortion** pattern, with data exfiltration (including use of `AZcopy`) preceding ransomware deployment, and has been observed impacting both Windows endpoints and **Nutanix** hypervisor environments. A key technical finding is Interlock’s use of a **Bring Your Own Vulnerable Driver (BYOVD)** technique to neutralize endpoint defenses. Researchers identified a custom tool dubbed **“Hotta Killer”** (associated with `polers.dll`) that drops a kernel driver `UpdateCheckerX64.sys`, described as a renamed vulnerable anti-cheat driver (`GameDriverx64.sys`, **CVE-2025-61155**). Because the driver is legitimate and digitally signed, it can pass initial trust checks; once loaded, it is abused for kernel-level process termination to **kill EDR/AV processes**, with reporting noting targeting of **Fortinet** security tooling specifically, enabling subsequent ransomware execution with reduced detection and response capability.
Jun 29, 2026