Microsoft has removed 119 malicious Microsoft Edge extensions, tied to a single actor active since at least 2021, that hid their payloads inside ordinary image and font files using steganography. The extensions posed as ad blockers, VPNs, translators, and similar tools, worked as advertised, and stayed dormant for days while passing evasion checks, which let them survive in the store for years and reach up to 2.6 million installs. Beyond ad fraud and affiliate hijacking, the more dangerous variants stole Google credentials and two-factor codes at sign-in, harvested WordPress admin logins, and exfiltrated cookies for session hijacking, with extra aggression against corporate and banking targets. Microsoft has published indicators of compromise.
HUMAN Security has detailed Trapdoor, an Android ad-fraud and malvertising operation that pushed 455 apps with more than 24 million combined Play Store downloads and drove an average of 659 million daily ad-bid requests, three-quarters of them from US devices. The operators run their own ad campaigns to recruit victims, then use legitimate install-attribution tools to switch on fraud only for users who came in through those campaigns, suppressing the bad behavior for anyone who installed organically - which kept Google's reviewers and most security researchers in the dark. Google has now removed all identified apps from the Play Store.
TrustStrike Labs