It's signed by Mozilla (extremely unlikely that's a virus unless they got hacked) and it's detected as trojan only by "max secure", a questionable snake oil product that is like a broken clock, correct only twice a day
I've been using computers for 30 years and never once has an antivirus program been helpful or accurate. But yeah, I don't download and click on random stuff from the web.
I have read on the firefox forum that this particular anti-malware engine flags these like that. I just want to know to be sure. Is there somewhere where I can check if it was officially generated by firefox (other than the signature which seems legit)