0-day attack on Firefox users stole password and key data: Patch now!

The bug in a built-in PDF reader allowed attackers to steal sensitive files stored on the hard drives of computers that used the vulnerable Firefox version. The attack was used against both Windows and Linux users, Mozilla researcher Daniel Veditz wrote in a blog post published Thursday.

"The exploit leaves no trace it has been run on the local machine," Veditz wrote. "If you use Firefox on Windows or Linux it would be prudent to change any passwords and keys found in the above-mentioned files if you use the associated programs. People who use ad-blocking software may have been protected from this exploit depending on the software and specific filters being used."