Secure Annex cybersecurity researcher John Tuckner has identified 57 malicious Chrome extensions that can be used to track your activities or run malware. Although most of the extensions in question aren’t available on the Chrome Web Store, they’ve still been downloaded over 6 million times, BleepingComputer reports.
The most popular of the extensions is called Cuponomia: Coupons and Cashback (with 700,000+ users), followed by Fire Shield Extension Protection and Total Safety for Chrome (with 300,000+ users each). You can view the full list of extensions in this spreadsheet.
Due to trickery like false promises of increased security and/or the potential to earn real-world money, many users have been lured into downloading these malicious extensions via ads or scam sites.
The malicious extensions found on the Chrome Web Store have been removed as of this writing, but it will be difficult—if not impossible—to tackle the ones spreading via other channels.
If you suspect you’ve downloaded a malicious Chrome extension, you should uninstall it immediately and change any passwords for any related accounts that may have fallen into the wrong hands.
Further reading: Key tips to make Google Chrome more secure