Zero day

Security Advisory

7Zip Mark-Of-The-Web Vulnerability

A high severity vulnerability in 7-Zip is exploiting in the wild. This vulnerability, identified as a Mark-of-the-Web (MoTW) bypass, allows attackers to craft a double archive file that, when extracted, bypasses MoTW protections.

OEM7Zip
SeverityHigh
CVSS7.0
CVEsCVE-2025-0411
Exploited in WildYes
Patch/Remediation AvailableYes
Advisory Version1.0

Overview

The vulnerability enables threat actors to create archives containing malicious scripts or executables, which, due to the flaw, will not receive the usual MoTW protection.

This exposes Windows users to potential attacks and has recently been added to the CISA Known Exploited Vulnerabilities Catalog. Furthermore, a Proof of Concept (PoC) for this vulnerability has been publicly released, increasing the risk of exploitation.

7-Zip vulnerability allows attackers to bypass the Mark of the Web (MotW) Windows security feature and was exploited by Russian hackers as a zero-day since September 2024.

Vulnerability NameCVE IDProduct AffectedSeverity
  MOTW Bypass vulnerability  CVE-2025-0411  7zip  High

Technical Summary

This vulnerability bypasses the Mark-of-the-Web (MoTW) feature, a security measure in Windows operating systems that flags files originating from the internet as potentially untrusted. MoTW is typically applied to files like downloaded documents, images, or executable files, which prompts a warning when opened. However, this vulnerability occurs when 7-Zip fails to properly propagate MoTW protections to files inside double-encapsulated archives.

An attacker can craft an archive containing another archive (a “double archive”), and 7-Zip did not properly propagate MoTW protections to the content to the inner archive.

This flaw allows any malicious content in the inner archive to be executed without triggering any security warnings. Consequently, this exposes Windows users to the risk of remote code execution and other malicious activities.

CVE IDSystem AffectedVulnerability DetailsImpact
CVE-2025-04117Zip Prior to v24.09    This flaw allows attackers to execute arbitrary code through double-encapsulated archives that bypass MoTW protections.Arbitrary remote code injection, potential system compromise

Remediation:

Update 7zip to v24.09 or the latest version. Installing the latest version will ensure that vulnerability is addressed, protecting systems from potential exploitation.

Generic Recommendations

  • Exercise Caution with File Extraction: Always verify the source before extracting files, especially from unfamiliar or untrusted sources.
  • Enhance User Awareness: Educate users on identifying phishing attempts and avoiding clicks on suspicious links or attachments.
  • Monitor for Anomalies: Continuously monitor systems for signs of exploitation, unusual file extraction behaviors, or unauthorized access attempts.

Conclusion

The MoTW bypass vulnerability in 7-Zip represents a serious security concern for Windows users, as it allows attackers to circumvent protective measures and execute malicious code. Updating to the latest version of 7-Zip is the recommended action to ensure systems are protected against this vulnerability.

References:

#CyberSecurity #7Zip #SecurityAdvisory #VulnerabilityManagement #CISO #CXO #PatchManagement #Intrucept

Security Advisory

Zero-Day Vulnerability in Microsoft Sysinternals Tools  

Summary 

A critical 0-Day vulnerability has been identified in nearly all Microsoft Sysinternals tools, allowing attackers to exploit DLL injection techniques to execute arbitrary code. This presents a significant risk to IT administrators and developers who rely on these utilities for system analysis and troubleshooting.

OEM Microsoft 
Severity High 
Date of Announcement 2025-02-05 
CVEs Not Yet Assigned 
Exploited in Wild No 
Patch/Remediation Available No 
Advisory Version 1.0 
Vulnerability Name Zero-Day  

Overview 

Despite being reported to Microsoft over 90 days ago, the vulnerability remains unpatched, as Microsoft considers it a “defense-in-depth” issue rather than a critical security flaw. 

Vulnerability Name CVE ID Product Affected Severity Impact 
            zero-day  Not Yet Assigned Microsoft Sysinternals Tools (Process Explorer, Autoruns, Bginfo, and potentially others)          High Arbitrary Code Execution, Privilege Escalation, Malware Deployment 

Technical Summary 

The vulnerability is caused by improper handling of DLL loading paths in affected Sysinternals utilities. When these tools search for required DLLs, they follow a specific search order, which may include untrusted locations such as network shares or user-writable directories. 

The issue arises from how Sysinternals tools prioritize DLL search paths, favoring untrusted directories such as: 

  • The Current Working Directory (CWD) 
  • Network locations (e.g., shared drives) 
  • User-writable paths over secure system directories 

This flaw allows attackers to place a malicious DLL in the same directory as a Sysinternals executable, tricking the application into loading the rogue DLL instead of the legitimate system DLL. 

Exploit Workflow 

  1. Attacker crafts a malicious DLL (e.g., cryptbase.dll or TextShaping.dll) containing a payload such as a reverse shell, ransomware, or trojan. 
  1. The DLL is placed in the same directory as a vulnerable Sysinternals tool. 
  1. The user unknowingly executes the tool (e.g., Bginfo.exe or procexp.exe) from that directory. 
  1. The malicious DLL is loaded instead of the legitimate system DLL. 
  1. Attackers gains code execution with the privileges of the running process (potentially SYSTEM privileges if run with admin rights). 

Recommendations 

  1. Avoid Running Sysinternals Tools from Network Locations 
  • Always copy tools to a local trusted directory before execution. 
  • Disable execution of .exe files from network drives if feasible. 
  1. Restrict DLL Search Paths 
  • Use SafeDLLSearchMode to prioritize secure directories. 
  • Implement DLL redirection to force tools to load DLLs from trusted paths. 
  1. Implement Application Control Policies 
  • Use AppLocker or Windows Defender Application Control (WDAC) to block unauthorized DLLs from loading. 
  • Restrict execution of Sysinternals tools to trusted admin-only directories. 
  1. Verify DLL Integrity Before Execution 
  • Use SigCheck (Sysinternals) to ensure all loaded DLLs are digitally signed. 
  • Block execution of unsigned or suspicious DLLs in sensitive directories. 
  1. Monitor for Suspicious DLL Loading Behavior 
  • Enable Sysmon logging to detect anomalous DLL loads (Event ID 7). 
  • Monitor for executions of Sysinternals tools from network shares (Event ID 4688). 

Conclusion 

Despite being responsibly disclosed to Microsoft in October 2024, the vulnerability in Sysinternals tools remains unpatched as of February 2025. Microsoft classifies it as a “defense-in-depth” issue, dismissing it as non-critical, while security researchers highlight its severe impact on enterprises, especially those running tools from network shares. This leaves users reliant on manual mitigations to avoid exploitation.

The Sysinternals tools, developed by Microsoft, are a widely-utilized suite of utilities designed to provide in-depth insights into the processes, services, and configurations of Windows systems. 

References: 

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