https://feed.craftedsignal.io/tags/memprocfs/Trending threats, MITRE ATT&CK coverage, and detection metadata — refreshed continuously.Hugoenhello@craftedsignal.iohello@craftedsignal.ioWed, 08 Apr 2026 22:16:23 +0000https://feed.craftedsignal.io/briefs/2026-04-memprocfs-dll-hijacking/Wed, 08 Apr 2026 22:16:23 +0000hello@craftedsignal.iohttps://feed.craftedsignal.io/briefs/2026-04-memprocfs-dll-hijacking/MemProcFS before 5.17 is susceptible to DLL and shared-library hijacking due to unsafe library-loading patterns, allowing attackers to achieve arbitrary code execution by placing malicious libraries or manipulating the library search path.MemProcFS before version 5.17 is vulnerable to DLL and shared library hijacking due to unsafe library loading practices. Specifically, the application uses bare-name LoadLibraryU and dlopen calls without proper path qualification for vmmpyc, libMSCompression, and plugin DLLs. This vulnerability, identified as CVE-2026-40031, exists across six attack surfaces. The vulnerability was reported by VulnCheck. Exploitation can occur on both Windows and Linux systems where MemProcFS is installed.

Attack Chain

1. Attacker identifies a vulnerable MemProcFS installation (version < 5.17).
2. Attacker determines the libraries MemProcFS attempts to load without a fully qualified path, such as vmmpyc, libMSCompression, or plugin DLLs.
3. Attacker crafts a malicious DLL or shared library with the same name as one of the targeted libraries (e.g., vmmpyc.dll on Windows or libvmmpyc.so on Linux).
4. Attacker places the malicious library in the same working directory as MemProcFS or manipulates the LD_LIBRARY_PATH environment variable (on Linux) to point to a directory containing the malicious library.
5. The user executes MemProcFS.
6. MemProcFS attempts to load the legitimate library using LoadLibraryU or dlopen.
7. Due to the presence of the malicious library in the working directory or the manipulated LD_LIBRARY_PATH, the malicious library is loaded instead of the intended legitimate library.
8. The malicious library executes arbitrary code within the context of the MemProcFS process, granting the attacker control over the system.

Impact

Successful exploitation of CVE-2026-40031 allows an attacker to achieve arbitrary code execution. While the exact number of victims is unknown, any system running a vulnerable version of MemProcFS is at risk. Given the nature of MemProcFS, successful exploitation could lead to sensitive data exposure or complete system compromise.

Recommendation

• Upgrade MemProcFS to version 5.17 or later to address the vulnerability (References: https://github.com/ufrisk/MemProcFS/releases/tag/v5.17).
• Monitor process creations for MemProcFS loading unexpected DLLs or shared libraries from non-standard paths using the provided Sigma rules.
• Implement file integrity monitoring for MemProcFS installation directories to detect the presence of newly created DLLs or shared libraries with suspicious names.
• Educate users about the risks of running applications from untrusted sources and the importance of verifying the integrity of software before execution.

]]>highadvisorydll-hijackinglibrary-hijackingcode-executionmemprocfscve-2026-40031https://feed.craftedsignal.io/briefs/2024-11-memprocfs-memory-dump/Sat, 02 Nov 2024 12:00:00 +0000hello@craftedsignal.iohttps://feed.craftedsignal.io/briefs/2024-11-memprocfs-memory-dump/Adversaries use MemProcFS, a memory forensics tool, to mount memory dumps as virtual file systems and extract sensitive information like credentials from LSASS or registry hives.MemProcFS is a memory forensics tool that allows users to mount physical memory as a virtual file system. While legitimate uses exist for forensic analysis, adversaries are abusing it to gain unauthorized access to sensitive information. Observed tactics involve mounting memory dumps of compromised systems and extracting credentials, LSA secrets, SAM data, and cached domain credentials. This activity is particularly concerning as it allows threat actors to bypass traditional security measures and directly access sensitive data within the memory space of targeted processes. Unapproved usage of MemProcFS should be considered suspicious and investigated immediately to prevent credential theft and lateral movement.

Attack Chain

1. The attacker gains initial access to a system through unspecified means (e.g., exploiting a vulnerability or using stolen credentials).
2. The attacker obtains a memory dump of the compromised system, which may contain sensitive information.
3. The attacker executes MemProcFS.exe with the -device parameter to mount the memory dump as a virtual file system.
4. MemProcFS creates a virtual file system representation of the memory dump, allowing the attacker to browse the memory space as files and directories.
5. The attacker accesses the memory of the LSASS process (lsass.exe) through the mounted file system.
6. The attacker extracts credentials, such as usernames and passwords, from the LSASS process memory.
7. The attacker may also access registry hives through the mounted file system to obtain LSA secrets, SAM data, and cached domain credentials.
8. The attacker uses the stolen credentials for lateral movement, privilege escalation, or data exfiltration.

Impact

Successful exploitation allows threat actors to steal sensitive information, including credentials, LSA secrets, SAM data, and cached domain credentials. Compromised credentials can be used for lateral movement within the network, privilege escalation, and further data breaches. The number of potential victims is unknown, but the severity of the impact is high due to the potential for widespread compromise. Sectors at risk include any organization that stores sensitive data on Windows systems.

Recommendation

• Deploy the Sigma rule “Detect MemProcFS Execution with Device Parameter” to your SIEM to identify suspicious use of MemProcFS based on process creation events.
• Enable Sysmon process creation logging to provide the necessary data for the Sigma rules above.
• Monitor for unusual file system access patterns that may indicate a memory dump being mounted as a virtual file system.

]]>highadvisorycredential-accessmemory-dumpmemprocfs