A North Korean-backed threat group tracked as Kimsuky is using a malicious browser extension to steal emails from Google Chrome or Microsoft Edge users reading their webmail.
The extension, dubbed SHARPEXT by Volexity researchers who spotted this campaign in September, supports three Chromium-based web browsers (Chrome, Edge, and Whale) and can steal mail from Gmail and AOL accounts.
The attackers install the malicious extension after compromising a target's system using a custom VBS script by replacing the 'Preferences' and 'Secure Preferences' files with ones downloaded from the malware's command-and-control server.
Once the new preferences files are downloaded on the infected device, the web browser automatically loads the SHARPEXT extension.
"The malware directly inspects and exfiltrates data from a victim's webmail account as they browse it," Volexity said Thursday.
"Since its discovery, the extension has evolved and is currently at version 3.0, based on the internal versioning system."
How Do I Protect Myself from Chrome Extension Malware?
Are browser extensions safe?
And How Should Organizations Resolve This Risk?
Whats different about the SHARPEXT threat to Gmail?
browser extension
chrome extension
north korean
malicious chrome
malicious browser
#backdoor #ransomware #fbi #maui #advisory #threat #cybersecurity #security