SysInternals

Threat actors associated with the Play ransomware operation exploited a zero-day vulnerability in Microsoft Windows, identified as CVE-2025-29824, before a patch was released on April 8, 2025. This vulnerability affects the Windows Common Log File System (CLFS) driver, allowing attackers to elevate their privileges to full system access. The Play ransomware group targeted an unnamed organization in the United States, likely gaining initial access through a public-facing Cisco Adaptive Security Appliance (ASA). During this intrusion, no ransomware payload was deployed; instead, the attackers used a custom information-stealing tool named Grixba. Microsoft attributed this activity to the threat group Storm-2460, known for deploying PipeMagic malware. The exploitation affected various sectors, including IT, real estate in the U.S., finance in Venezuela, software in Spain, and retail in Saudi Arabia. The vulnerability received a CVSS score of 7.8 and was addressed in Microsoft's April 2025 Patch Tuesday updates. The attack involved creating files in the path C:ProgramDataSkyPDF, injecting a DLL into the winlogon.exe process, extracting credentials from LSASS memory, creating new administrator users, and establishing persistence. The Play ransomware group has been active since June 2022 and employs double-extortion tactics. Organizations are urged to apply the security updates released on April 8, 2025, especially for vulnerable Windows versions, while Windows 11 version 24H2 is not affected due to existing security mitigations.