
Proof-of-concept and technical analysis of CVE-2025-0411, a 7-Zip Mark-of-the-Web bypass vulnerability exploited in SmokeLoader campaigns, with adversarial techniques and defensive measures.
CVE-2025-0411 is a flaw in 7-Zip that bypasses Windows' Mark-of-the-Web (MoTW), allowing malicious files from crafted archives to execute without warnings. Exploited in SmokeLoader campaigns, it poses risks due to 7-Zip’s lack of auto-updates.
MoTW marks internet-downloaded files as unsafe via an Alternate Data Stream (ADS), triggering warnings or Protected View. It’s only effective if preserved during file handling.
7-Zip fails to propagate MoTW’s Zone.Identifier ADS to files extracted from nested archives, enabling silent execution of malicious content.
CVE-2025-0411 shows the danger of MoTW bypasses. With a patch available but no auto-updates, proactive updates and awareness are key to reducing risk.