Browser Extension's Logo containing malware

  GhostPoster malware. 
Browser extensions can have a logo. An icon displayed as part of the browser extension.
GhostPoster malware adds JavaScript after a marker. 
So the extension displays the logo and executes the extension function as normal.
BUT the PNG logo delivers the malicious JavaScript code past most defenses.

Seven years undetected. 8 million instances, over 1 million victims.

Even more stealth. The malware loader uses several sites. The loader waits 48 hours. The loader only executes the load 10% of the time. 

Information on GhostPoster in recent.