According to user comments here FBI Ransomware Now Targeting Apple's Mac OS X Users | Malwarebytes Unpacked
Ransomware has infected Firefox in a Linux distro.....(zorin OS 6.0)
You can block the scripting used to infect Firefox by using the NoScript Add-on.
If you do get the Ransomware popups it is likely that all you have to do is clean up the Firefox cache. I use BleachBit
to vacuum Firefox as well. BleachBit is similar to Ccleaner.
Whether Chrome is targeted or not I don't know. But the same would likely apply....delete the cache if the Ransomware popups/ windows
EDIT: To protect your Firefox further, regularly backup your Firefox profile in case it gets corrupted by crapware such as this or for
other reasons and you need to remove it. If you need help doing that: Back up and restore information in Firefox profiles | Firefox Help
Edited by buddy215, 22 December 2013 - 01:06 PM.