I just went to use my mum's PC whilst she's busy, and I saw that she was using FF (halleluiah)

However there was a popup.. which I thought was odd for ol' FF

This is what was in the add bar: URL REMOVED TO PREVENT INFECTING OTHERS

And it says "If automated download does't start please Click Here or select "Run" or "Open" when promted."
And thats all, with a pic of a globe and some coloured arrows coming out of it.

I'm really not sure. When I try to close it, I am asked if I want to navigate away from the page. It tells me a Virus Signature has been detected which could cause erratic behaviour etc. And says click "ok" to continue "Cancel" to go back, which takes me back to the page. As soon as I try to exit FF asks me if I want to save the file AtnvrsInstall.exe which is from URL REMOVED TO PREVENT INFECTING OTHERS

I don't want to install but it doesn't want to let me navigate away.
I'm worried that if Mum had seen it should would have just clicked to save it :/ I thought FF prevented such things?

Welp

I'm goona ask ;to start with to see if she is properly 'protected'

what is her antivirus protection and other protection programs and when were they all last fully updated and run on full system scans?plus the windows version on there?

Press CTRL-ALT-DEL to bring up Task Manager.
Kill the Firefox process.
Restart Firefox - Choose New Session
Firefox menu bar click Tools - Options
Click Privacy tab - Clear Private data
Do virus scan.

I've done a few virus scans and its picked up one or two nasties.
Windows XP SP1, Norton Anti-V

can you please run an on line scan with trend

http://housecall.trendmicro.com/uk/
the first attemp may take a wee while while it loads the program and runs the scan

let us know what nasties it finds

Moving this to the Am I Infected forum.
Why haven't you installed SP2?

I think it is ( I was rushing when I was typing, I was never any good at typing numbers!
I shall do that next time I am on her PC. Thankyou.
So... how should I prevent this happening in the future to my muzzer in the future, my Bleepinglings?

Until your mum learns proper computer security it would be better to create another admin account and change her's to limited user

that's the safest way to protect her from herself, the best AV in the world doesn't do any good when the admin controlling the computer says go ahead and install that malware

install the noscript addon for firefox and teach her how to use it