EDR Archives

Winsage

April 9, 2025

Exploitation of CLFS zero-day leads to ransomware activity

The Microsoft Threat Intelligence Center (MSTIC) and Microsoft Security Response Center (MSRC) identified a zero-day elevation of privilege vulnerability in the Windows Common Log File System (CLFS), designated as CVE-2025-29824. This vulnerability has been exploited by the PipeMagic malware, attributed to the group Storm-2460, affecting organizations in various sectors across the U.S., Venezuela, Spain, and Saudi Arabia. Microsoft released security updates on April 8, 2025, to address this vulnerability. The exploit allows attackers with standard user privileges to escalate their access, and it was executed from a dllhost.exe process. The exploit utilizes memory corruption techniques and the RtlSetAllBits API to gain all privileges and inject processes into SYSTEM processes. Post-exploitation, the attackers injected a payload into winlogon.exe, leading to ransomware activity characterized by file encryption and the creation of ransom notes. Indicators of compromise include the creation of a CLFS BLF file at C:ProgramDataSkyPDFPDUDrv.blf, command lines associated with ransomware activities, and specific domains linked to PipeMagic. Microsoft advises applying security updates promptly and recommends strategies for mitigating ransomware threats, including enabling cloud-delivered protection and utilizing device discovery.

Winsage

April 8, 2025

Microsoft fixes actively exploited Windows CLFS zero-day (CVE-2025-29824)

April 2025 Patch Tuesday introduced fixes for over 120 vulnerabilities, including a critical zero-day vulnerability (CVE-2025-29824) that is actively exploited. CVE-2025-29824 is a user-after-free vulnerability in the Windows Common Log File System (CLFS), allowing privilege escalation to SYSTEM on compromised Windows machines. Microsoft has patched 32 CLFS vulnerabilities since 2022, with six exploited in the wild. Updates for Windows 10 are not yet available. Other notable vulnerabilities include CVE-2025-26663 and CVE-2025-26670, both unauthenticated user-after-free vulnerabilities in Windows LDAP, and CVE-2025-27480 and CVE-2025-27482 in Windows Remote Desktop Services. None of these vulnerabilities have been patched for Windows 10 systems, but updates are forthcoming. Microsoft reversed its decision to discontinue driver update synchronization to WSUS servers, confirming that WSUS will continue to synchronize driver updates.

Tech Optimizer

April 7, 2025

Sakura RAT Released on GitHub Can Bypass Antivirus and EDR Tools

Sakura RAT is a newly developed remote administration tool available on GitHub, designed for use by malware analysts and security researchers. It features capabilities such as hidden browsing, hidden virtual network computing (HVNC), fileless execution, multi-session control, and anti-detection mechanisms to evade antivirus and endpoint detection systems. While marketed for research purposes, its open availability raises concerns about potential misuse by cybercriminals for activities like data exfiltration and ransomware deployment. Cybersecurity experts are advocating for the removal of the repository from GitHub and calling for improved detection systems to combat the risks posed by such advanced tools.

Tech Optimizer

March 31, 2025

Traditional EDR can’t keep up with modern cyber threats

By 2025, the global cost of cybercrime is projected to reach .5 trillion annually. Many organizations continue to use outdated Endpoint Detection and Response (EDR) solutions, which are increasingly ineffective against sophisticated cyber threats. EDR was introduced in 2013 but has struggled to keep pace with evolving attack techniques. Traditional EDR is reactive, responding to incidents after they occur, and relies on known Indicators of Compromise (IoCs), which limits its effectiveness. Real-world examples of traditional EDR failures include a misconfigured update to CrowdStrike’s Falcon EDR causing an IT outage, the Akira ransomware exploiting an unsecured webcam, the Medibank breach despite multiple alerts from EDR, and the BlackCat ransomware attack on Henry Schein. These incidents highlight the inadequacy of traditional EDR in preventing modern threats. The next phase of endpoint security is Preemptive Endpoint Protection (PEP), which actively prevents attacks rather than just detecting and responding to them. PEP utilizes proactive strategies like Automated Moving Target Defense (AMTD) and Adaptive Exposure Management (AEM), and research indicates that organizations using proactive security save 30% more on breach costs compared to those relying solely on reactive measures.

Tech Optimizer

March 31, 2025

Ransomware crews add EDR killers to their arsenal

Antivirus and endpoint security tools are increasingly challenged by ransomware groups that use sophisticated strategies to disable defenses early in attacks. Cisco Talos reported that in nearly half of the ransomware incidents they handled in 2024, attackers successfully employed "EDR killers" to neutralize endpoint detection and response (EDR) systems, achieving success 48 percent of the time. Tools such as EDRSilencer, EDRSandblast, EDRKillShifter, and Terminator pose significant threats to organizational security. EDRKillShifter exploits vulnerable drivers on Windows machines to terminate EDR products, a tactic observed in operations by rival gangs like Medusa, BianLian, and Play. The primary goal of these tools is to disable EDR protections, allowing attackers to operate undetected, complicating system recovery efforts. Recovery often requires wiping and rebuilding entire networks if robust backups are available. Some EDR killers, like HRSword, are legitimate software tools misused by ransomware actors to disable endpoint protection systems. Attackers have exploited misconfigured systems, particularly EDR products set to audit-only mode, which detect but do not block malicious activity. LockBit has remained the most active ransomware-as-a-service group for the third consecutive year, accounting for 16 percent of claimed attacks in 2024. Newcomer RansomHub secured the second position with 11 percent of posts to leak sites. The effectiveness of law enforcement actions plays a significant role in shaping the ransomware landscape.

Tech Optimizer

March 23, 2025

Cybercriminals Exploit CheckPoint Driver Flaws in Malicious Campaign

A report by Nima Bagheri reveals that CheckPoint’s ZoneAlarm antivirus software is being exploited by threat actors using a method called Bring Your Own Vulnerable Driver (BYOVD). This attack targets vulnerabilities in the vsdatant.sys driver, which operates with high-level kernel privileges, allowing attackers to bypass Windows security measures. Specifically, version 14.1.32.0 of vsdatant.sys, released in 2016, contains vulnerabilities that enable attackers to circumvent the Windows Memory Integrity feature, gaining access to sensitive information and establishing persistent connections to compromised systems. Bagheri advises users to update to the latest version of vsdatant.sys, which is not vulnerable. CheckPoint confirmed that the outdated driver is no longer in use and that users running the latest versions of ZoneAlarm or Harmony Endpoint are not affected.

Winsage

March 7, 2025

Akira Ransomware Targets Windows Servers via RDP and Evades EDR with Webcam Trick

The Akira ransomware group has demonstrated its ability to bypass Endpoint Detection and Response (EDR) tools by exploiting an unsecured webcam. In 2024, Akira was responsible for 15% of ransomware incidents addressed by the S-RM team. The group typically gains access through remote access solutions and uses tools like AnyDesk.exe. In a recent attempt to deploy ransomware on a Windows server, their initial effort was thwarted by EDR detection. Subsequently, they conducted an internal network scan and targeted a vulnerable webcam, which lacked EDR protection. By compromising the webcam, Akira deployed Linux-based ransomware to encrypt files across the victim’s network. This incident highlights the need for organizations to patch and manage IoT devices, audit networks for vulnerabilities, implement network segmentation, and monitor IoT traffic for anomalies.

Tech Optimizer

March 3, 2025

Hackers Using PowerShell and Microsoft Legitimate Apps to Deploy Malware

Cybersecurity experts are reporting an increase in fileless attacks, where cybercriminals use PowerShell and legitimate Microsoft applications to deploy malware with minimal traces. These attacks have existed for over twenty years and are effective at evading traditional antivirus solutions. Attackers exploit PowerShell to download and execute malicious payloads directly in memory, complicating detection. They also utilize LOLBAS techniques, manipulating legitimate applications like BITS to execute malware. Memory injection techniques, such as Process Hollowing, allow attackers to disguise malware as legitimate processes. To combat these threats, cybersecurity professionals recommend deploying Endpoint Detection and Response solutions, enhancing memory analysis, enabling comprehensive PowerShell logging, and implementing PowerShell Constrained Language Mode. Organizations should also monitor Active Directory and conduct regular vulnerability assessments. Traditional file-based security measures are inadequate against these evolving threats, necessitating a shift to behavior-based detection and robust monitoring.

Tech Optimizer

February 27, 2025

New Malware Uses Legitimate Antivirus Driver to Bypass All System Protections

Cybersecurity researchers at Trellix have identified a malware campaign utilizing a legitimate antivirus driver, specifically the Avast Anti-Rootkit driver (aswArPot.sys), to gain kernel-level access and bypass security protocols. The malware, named “kill-floor.exe,” deploys the Avast driver as a file called “ntfs.bin” and registers it as a service using the Service Control utility (sc.exe) to obtain unrestricted privileges. It monitors active processes and terminates security-related processes by communicating with the Avast driver through the DeviceIoControl API. The malware exploits kernel-mode capabilities to execute actions that dismantle system defenses. Organizations are advised to implement BYOVD protection strategies, including detection rules for vulnerable drivers. Key indicators associated with this campaign include the MD5 hashes: 40439f39f0195c9c7a3b519554afd17a (kill-floor.exe) and a179c4093d05a3e1ee73f6ff07f994aa (ntfs.bin).