StegoAd is a threat campaign tracked across 2 threat clusters and 6 intelligence report mentions on ThreatCluster. First observed June 29, 2026; most recent activity July 14, 2026.
The ModHeader browser extension, used by approximately 1.6 million users across Chrome and Edge, was removed after researchers discovered a dormant data-collection capability embedded in its signed release. The…
Microsoft has dismantled the StegoAd operation, removing 119 malicious Edge extensions that used steganography to hide malware within image and font files. The campaign, active since 2021, targeted over 2.6 million…