Virus on facebook?

While visiting my Mother earlier she was on Facebook and clicked on a game called Zuma which she plays regularly. While the game was loading, Avast popped up saying Malware was blocked. It said infection HTML:Iframe-inf. I have put the link below with a screenshot of the warning. Is this a false positive or something serious?

She uses Avast free on windows 7 64bit.

hxxp://ox-labs.popcap.com/www/delivery/afr.php?cb=42509172&zoneid=52|>{gzip}

its not false positive, that link is for showing up external ads, and one of the ads are infected, so you got the warning.

Okay, thanks for letting me know.