Basicly it is a virus.
i think it was downloaded when firefox did and update.
thats all i can think of
i found 14 viruses from trojen to malware on my site, if i go to my control panel it shows me all my files and dated they have been modified
and they were all done when i turned the pc on.
so its got to of been some kind of update.
all i have done was back up my site and download it to my pc run ith through avast and then removed them,
upload it back to my site and they warnings have gone,