Avast! Threat has been detected, what? Infection: HTML:Iframe-inf?

Greetings from Spain! I'm just having the same problem you describe. I'm using Avast since few years without any problem, but today it's always disturbing with an alert about a "html:frame-inf" infection in almost every web pages I try to navigate at, making impossible to access many of them, or loading them instead with many bugs. It doesn't matter if I use Chrome, Explorer, or Firefox: the problem is the same. I was wondering I had a virus attack since I visited this forum. I am now changing my anti virus protection to AVG. I think this is too unacceptable for an anti virus protection, even if it's Avast. What a pity, Good Luck!