Introduction: Why It Matters
Researchers have identified a security concern involving 7-Zip Mark-of-the-Web Bypass that could reduce one of Windows’ most important security protections. The issue occurs because extracted files do not automatically inherit Mark-of-the-Web (MotW) metadata when users extract archives using 7-Zip’s default settings.
Without this metadata, Windows SmartScreen may not display its usual security warning before a downloaded executable is launched. Although the 7-Zip Mark-of-the-Web Bypass is not a software vulnerability or a newly assigned CVE, attackers could abuse the behavior to make phishing campaigns more convincing by distributing malicious ZIP files that appear legitimate.
As phishing attacks continue to evolve, organizations should understand how this security configuration can affect endpoint protection and what steps can reduce the associated risks.
What is Mark-of-the-Web (MotW)?
Mark-of-the-Web (MotW) is a Windows security feature that labels files downloaded from the internet by attaching an alternate data stream called Zone.Identifier.
When a user opens a file carrying this metadata, Windows can trigger additional security controls, including:
- Microsoft SmartScreen warnings
- Office Protected View
- Enhanced application security checks
- User confirmation before execution
These protections help users recognize potentially unsafe files before they are executed. Microsoft explains how SmartScreen and Windows security features help identify potentially unsafe downloads in its Microsoft SmartScreen documentation.
What Caused the Issue?
The reported 7-Zip Mark-of-the-Web Bypass is not caused by malicious code or a programming flaw inside 7-Zip itself.
Instead, researchers observed that 7-Zip version 24.09 does not propagate the Zone.Identifier stream by default when extracting ZIP archives.
As a result:
- Downloaded ZIP files may contain MotW metadata.
- Files extracted through 7-Zip lose that metadata.
- Windows SmartScreen may treat the extracted executable as a local file.
- Users may not receive the expected warning before launching it.
Windows 11 File Explorer preserves Mark-of-the-Web information during ZIP extraction, but 7-Zip requires users to manually enable the “Propagate Zone.Id stream” option.
7-Zip Mark-of-the-Web Bypass: Technical Breakdown
Timeline of Events
Researchers recently highlighted that the default behavior of 7-Zip 24.09 does not preserve Mark-of-the-Web metadata during archive extraction. The 7-Zip Mark-of-the-Web Bypass finding has renewed discussions around security tool configurations rather than software vulnerabilities.
Microsoft’s Windows 11 File Explorer already preserves MotW during ZIP extraction, reducing this specific risk for users who rely on the native extraction feature.
How Attackers Could Abuse This Behavior
Although no exploit exists within 7-Zip itself, attackers could incorporate 7-Zip Mark-of-the-Web Bypass behavior into phishing campaigns.
A possible attack chain may include:
- Sending phishing emails containing ZIP attachments.
- Naming archives as invoices, software updates, tax documents, or shared files.
- Encouraging recipients to extract the archive using 7-Zip.
- Delivering executable files without the expected SmartScreen warning.
- Increasing the likelihood that victims execute malicious programs.
This technique does not bypass antivirus software directly but may reduce an important layer of user awareness provided by Windows.
Systems Potentially Affected
The following environments may be exposed to this configuration issue:
- Systems using 7-Zip 24.09 with default settings
- Windows devices relying on SmartScreen alerts
- Organizations that widely deploy 7-Zip
- Users extracting files received through email or messaging platforms
- Enterprises without endpoint policies enforcing Zone.Identifier propagation
Potential Risks & Impact
Increased Phishing Success
The absence of a SmartScreen warning may create a false sense of trust for users. Cybercriminals frequently disguise malicious ZIP archives as invoices, software updates, delivery notifications, or shared business documents. If users extract these archives with default 7-Zip settings, they may unknowingly execute harmful files without the additional warning normally provided by Windows.
Business Security Risk
Organizations that rely on SmartScreen as part of their layered security strategy could see reduced protection if employees routinely use 7-Zip without enabling Zone.Identifier propagation. While endpoint detection and antivirus solutions remain important defenses, losing an additional security prompt can increase the likelihood of successful social engineering attacks.
Compliance Considerations
Although this issue is not a software vulnerability, security teams should review endpoint configurations and archive management policies. Organizations operating under frameworks such as ISO/IEC 27001, NIST Cybersecurity Framework, or CIS Controls should ensure security tools are configured to preserve Windows security metadata wherever possible.
Official Response
At the time of writing, there is no CVE assigned for this behavior because it is considered a security configuration issue rather than a software vulnerability.
Researchers have highlighted that enabling “Propagate Zone.Id stream” within 7-Zip restores Mark-of-the-Web metadata to extracted files, allowing Windows SmartScreen to function as intended. Users can also use the built-in Windows 11 File Explorer for ZIP extraction, which preserves MotW by default.
Industry Context: Why This Matters
The 7-Zip Mark-of-the-Web Bypass demonstrates how modern phishing attacks increasingly rely on bypassing user security awareness rather than exploiting complex software vulnerabilities. Attackers continuously look for legitimate tools or default configurations that can reduce visible security warnings and improve the success rate of malware delivery.
Recent campaigns have shown that seemingly harmless archive files remain one of the most effective initial access methods. Security awareness, secure endpoint configurations, and layered defenses remain essential for reducing these risks.
As latest phishing and malware campaigns continue to evolve, following cybersecurity awareness best practices and staying informed about security compliance updates can help organizations strengthen their overall cyber resilience.
How to Protect Yourself and Your Organization
- Enable “Propagate Zone.Id stream” in 7-Zip settings.
- Prefer Windows 11 File Explorer for extracting downloaded ZIP files whenever practical.
- Never assume a file is safe simply because SmartScreen does not display a warning.
- Keep 7-Zip, Windows, and endpoint security software updated with the latest releases.
- Train employees to verify unexpected email attachments before opening them.
- Deploy endpoint protection capable of detecting suspicious executables even without SmartScreen prompts.
- Block executable attachments from unknown or untrusted email sources whenever possible.
Organizations and individual users can also follow the CISA phishing protection guidance for additional best practices on identifying phishing emails, handling suspicious attachments, and reducing the risk of malware infections.
Key Takeaways
- Default 7-Zip settings do not preserve Mark-of-the-Web metadata during extraction.
- The issue is not a new vulnerability or CVE but a security configuration concern.
- Missing MotW metadata may prevent Windows SmartScreen from displaying warning prompts.
- Attackers could abuse this behavior to improve phishing success rates.
- Enabling Zone.Identifier propagation significantly reduces this risk.
Conclusion: 7-Zip Mark-of-the-Web Bypass
The 7-Zip Mark-of-the-Web Bypass finding demonstrates that secure configurations are just as important as software patches. Even without a software vulnerability, a missing security warning can increase the effectiveness of phishing campaigns that rely on user trust.
Organizations should review how archive extraction tools are configured, educate users about suspicious attachments, and maintain multiple layers of endpoint protection. As phishing techniques continue to evolve, relying solely on SmartScreen warnings is no longer sufficient to defend against modern cyber threats.
Frequently Asked Questions(FAQs)
The 7-Zip Mark-of-the-Web Bypass refers to the default behavior in 7-Zip 24.09 where extracted files do not inherit Mark-of-the-Web metadata. As a result, Windows SmartScreen may not display its usual security warning before certain files are opened.
No. Researchers describe it as a security configuration issue rather than a software vulnerability. No CVE has been assigned for this behavior.
Mark-of-the-Web allows Windows to identify files downloaded from the internet and apply additional security protections, including SmartScreen warnings and Protected View in Microsoft Office.
Yes. Attackers may distribute malicious ZIP archives through phishing emails and rely on the missing SmartScreen warning to make malicious files appear more trustworthy.
Users should enable “Propagate Zone.Id stream” in 7-Zip, keep security software updated, and avoid opening unexpected attachments from unknown senders.