While surfing on the internet an Avast! pop-up suddenly appeared.
It said some url had been blocked. When I look in the web shield
application a url has been blocked indeed. Do I have to be affraid my computer
has been infected? MBAM and Avast! scan didn’t show anything.
I would think that if avast said it blocked it that’s exactly what it did.
Yes, I also think you are fine. Avast did its job!
If you have run a ‘Full System’ Scan with MBam (with most recent update!!) and a Boot time scan with Avast, just to put your mind at rest(probably not necessary though), then as Craigb has already advised, the site was blocked…it should all be good 
Avast protects you by blocking sites that it believes may contain malware that might infect your computer. It is possible to get infected if you visit a site that has malicious javascript.
This section is not for posting viruses or false alarms
- When web shield blocked a thread and the mbam & avast scans says that your PC is clear then is clear
- Avast! did a good job as always!
A lot of sites right now that are fake, my web shield has blocked many lately…mostly just looking for call of duty black ops backgrounds for my son…google images