Which website, please, post hxxp (edited link, not live).
Generally, avast detection is accurate in these cases.
Isn't it an encrypted/obfuscated script or iframe?
Wasn't the site hacked?
Maybe you could contact its webmaster.
Check
here how to clean and make a website secure.
The vast majority of malware today is distributed over the web, mostly by means of hacked (otherwise legitimate) sites. The attacker usually injects malicious some scripts into some (or all) pages on the site, waiting for an unsuspecting user to visit the site and possible infect his/her machine.
And this is where avast’s detection capabilities really excel. Its abilities to detect these web-based malicious scripts are second to none, and thanks to the Web Shield and Script Blocking providers, they are used exactly when needed, doing an excellent job stopping the web-based malware right on the entry point.
