My first question…are you 100% sure it was infected?
There is minor problem with most AV software these days…it tends to err on the side of ‘everything is infected’, so there is time spent disinfecting a clean system and time spent worrying if you got everything cleaned up. Often various system tools/utilities (especially those that deal with network monitoring and ‘in depth’ security tools) are flagged like this.
The downside is, if ‘everything’ is a threat then, people tend to become desensitized so when something really happens, they are caught by surprise.
It’s always best to get at least one ‘second’ opinion on a suspect file…if not more than one. No single AV package is 100% against everything out there. (On the other hand, running multiple AV apps at the same time is a recipe for disaster.)
A good place to check out a suspect file against multiple AVs is…
http://virusscan.jotti.org/en
You simply upload it and let them scan it.
SY…FF’s scan is as accurate as your resident AV program. That’s what it uses, by default (and MS Security Essentials, if that’s all you’ve got on your system).