BYOVD | Breaking Cybersecurity News | The Hacker News

The threat actor linked to the exploitation of the recently disclosed security flaws in Microsoft SharePoint Server is using a bespoke command-and-control (C2) framework called AK47 C2 (also spelled ak47c2) in its operations. The framework includes at least two different types of clients, HTTP-based and Domain Name System ( DNS )-based, which have been dubbed AK47HTTP and AK47DNS, respectively, by Check Point Research. The activity has been attributed to Storm-2603 , which, according to Microsoft, is a suspected China-based threat actor that has leveraged the SharePoint flaws – CVE-2025-49706 and CVE-2025-49704 (aka ToolShell) – to deploy Warlock (aka X2anylock) ransomware. A previously unreported threat cluster, evidence gathered following an analysis of VirusTotal artifacts shows that the group may have been active since at least March 2025, deploying ransomware families like LockBit Black and Warlock together – something that's not observed commonly among established e-c...

The threat actors behind the Medusa ransomware-as-a-service (RaaS) operation have been observed using a malicious driver dubbed ABYSSWORKER as part of a bring your own vulnerable driver ( BYOVD ) attack designed to disable anti-malware tools. Elastic Security Labs said it observed a Medusa ransomware attack that delivered the encryptor by means of a loader packed using a packer-as-a-service (PaaS) called HeartCrypt. "This loader was deployed alongside a revoked certificate-signed driver from a Chinese vendor we named ABYSSWORKER, which it installs on the victim machine and then uses to target and silence different EDR vendors," the company said in a report. The driver in question, "smuol.sys," mimics a legitimate CrowdStrike Falcon driver ("CSAgent.sys"). Dozens of ABYSSWORKER artifacts have been detected on the VirusTotal platform dating from August 8, 2024, to February 25, 2025. All the identified samples are signed using likely stolen, revoked ce...

Cybersecurity researchers have uncovered a new malicious campaign that leverages a technique called Bring Your Own Vulnerable Driver ( BYOVD ) to disarm security protections and ultimately gain access to the infected system. "This malware takes a more sinister route: it drops a legitimate Avast Anti-Rootkit driver (aswArPot.sys) and manipulates it to carry out its destructive agenda," Trellix security researcher Trishaan Kalra said in an analysis published last week. "The malware exploits the deep access provided by the driver to terminate security processes, disable protective software, and seize control of the infected system." The starting point of the attack is an executable file (kill-floor.exe) that drops the legitimate Avast Anti-Rootkit driver, which is subsequently registered as a service using Service Control (sc.exe) to perform its malicious actions. Once the driver is up and running, the malware gains kernel-level access to the system, allowing it...

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Cybersecurity researchers have discovered a new cryptojacking campaign that employs vulnerable drivers to disable known security solutions (EDRs) and thwart detection in what's called a Bring Your Own Vulnerable Driver ( BYOVD ) attack. Elastic Security Labs is tracking the campaign under the name REF4578 and the primary payload as GHOSTENGINE. Previous research from Chinese cybersecurity firm Antiy Labs has codenamed the activity as HIDDEN SHOVEL. "GHOSTENGINE leverages vulnerable drivers to terminate and delete known EDR agents that would likely interfere with the deployed and well-known coin miner," Elastic researchers Salim Bitam, Samir Bousseaden, Terrance DeJesus, and Andrew Pease said . "This campaign involved an uncommon amount of complexity to ensure both the installation and persistence of the XMRig miner." It all starts with an executable file ("Tiworker.exe"), which is used to run a PowerShell script that retrieves an obfuscated Power...

Multiple threat actors are exploiting the recently disclosed security flaws in JetBrains TeamCity software to deploy ransomware, cryptocurrency miners, Cobalt Strike beacons, and a Golang-based remote access trojan called Spark RAT. The attacks entail the exploitation of  CVE-2024-27198  (CVSS score: 9.8) that enables an adversary to bypass authentication measures and gain administrative control over affected servers. "The attackers are then able to install malware that can reach out to its command-and-control (C&C) server and perform additional commands such as deploying Cobalt Strike beacons and remote access trojans (RATs)," Trend Micro  said  in a new report. "Ransomware can then be installed as a final payload to encrypt files and demand ransom payments from victims." Following public disclosure of the flaw earlier this month, it has been weaponized by threat actors associated with  BianLian  and  Jasmin ransomware  families, as well...