If Malwarebytes detected the file, it may have already deleted it and it's gone.. Or because it's a .tmp file, it could have automatically been removed when the browser was closed and may indeed be a false positive.. That said, you might want to try a second tool, such as the free SuperAntispyware program below.. Download, install, update, then run a full system scan while in "normal" Windows.. If there is any malware in operation, it should be running, and therefore detectable, while in Windows. Run Malwarebytes again also, while in "normal" Windows.
SUPERAntispyware Removal Tool
As to being sure of cleanliness after running multiple scanning tools... Well, you're never "absolutely" certain of such as there may be a new type of malware that hasn't reached the definitions of the best removal tools. But.. you'll be as certain as you can be simply because you've done your best to check.
Hope this helps.
I got a "malware.packer.gen" threat from my Malwarebytes Anti malware complete scan last night on a tmp file.
I didn't take any action and exited MBAM, went to that location, and couldn't find the file. So I did another complete scan (without updating the db version) with MBAM, and the second scan came out clean.
During both scans I only had one firefox browser running (same web page), and had no other application running.
Is there any way to figure out if this is a FP, since I can't even find that file? And, can I be sure that my system is clean once I've done a few complete scans (in regular mode and safe mode) with a few AV products?
I have Windows Vista SP2. Thank you very much for your help.