When clicking on to web links on Google I keep getting a red square popping up from Avast reading ‘Malicious URL Blocked’ and it blocks me from accessing the web site.
Any ideas how I can fix this ?
Yes…the website owner need to clean it for malware. 
or are you saying it happens on all links in google. ?
Can you attach a screen shot of the avast warning ?
@the OP: links to those sites? (neutralized when you post them >>> hxxp )
yesterday it was happening on every Google link, it came up when logging on this mornig, Avast ran a complete boot scan but found no viruses. So far today it seems to be working fine.
again, screen shots of Avast alerts please