Four Malicious Chrome Extensions Impacted More than Half a Million Users

Security researchers from Cybersecurity firm ICEBRG detected four malicious chrome extensions that impacted more than half a million people.

The initial investigation started after they noticed an unusual traffic flow in one of their client workstation, it appears like attackers use the extensions to conduct click fraud for generating more revenue or for SEO purpose.

Four Malicious Chrome Extensions

Change HTTP Request Header

Researchers identified the HTTP traffic is to the domain change-request[dot]info from the malicious chrome extension “Change HTTP Request Header”. And the control server at change-request[dot]info returns obfuscated Javascript.

The Javascript creates a WebSocket tunnel with change-request[dot]info control server and the WebSocket to proxy victim browser traffic. Attackers utilized it for running a click fraud ad campaign. ICEBRG published a detailed report on extension behaviors.

Nyoogle – Custom Logo for Google and Lite Bookmarks

Like Change HTTP Request Header, Nyoogle and Lite Bookmarks utilize a similar mix of allowing ‘unsafe-eval’ through the CSP with periodical configuration

Stickies – Chrome’s Post-it Notes

It also enables the ‘unsafe-eval’ via the CSP but uses obfuscation methods to retrieve the external javascript.

Chrome Extensions continue to get compromised, the initial compromise on Aug1, attackers used Copyfish extension to spread spam. Malware files have a size far beyond the ordinary and far beyond what is usually inspected for anti-virus solutions.

Now even the Chrome extension started mining cryptocurrency, a chrome extension Archive Poster with more than 105,000 users Caught injecting an in-browser cryptocurrency miner.

Chrome announced site isolation with Chrome 63 which allows each website to have a dedicated process isolated from other sites, allows to Whitelist or Blacklist specific extensions.