GhostPoster: Steganography Malware

GhostPoster Attacks Hide Malicious JavaScript in Firefox Addon Logos

GhostPoster that compromised over 50,000 Firefox browsers by concealing malicious JavaScript code within the logo images of popular extensions using a technique called steganography. This threat avoids detection through delayed activation (48 hours) and probabilistic payload delivery, making it extremely difficult for standard security tools to identify. Once active, the malware performs financial fraud by hijacking affiliate links, injects pervasive tracking code onto every website visited, and weakens browser defenses by stripping security headers. The text concludes with an urgent call for users to manually remove the compromised extensions and for businesses to adopt proactive extension whitelisting and specialized browser security audits to defend against such complex, evasive threats. ... Read More