It is the avast Network Shield blocking the site:
Cleaning the site, whilst that helps, it is also important to find the cause of the hack or it could happen again.

This is commonly down to old content management software being vulnerable, PHP, Joomla, Wordpress, SQL, etc. etc.

If you are sure that it is now clean and any potential exploit closed, etc. you can ask for it to be reviewed again.
There is an on-line contact form, http://www.avast.com/contact-form.php?loadStyles for: * Sales inquiries; Technical issues; Website issues; Report false virus alert in file; Report false virus alert on website; Undetected Malware; Press (Media), issues.

  • If you are reporting an FP, then you get another input field open, enter the web URL for the site you wish to submit for Network Shield review (image2), etc. A link to this topic also wouldn’t hurt.