Before we go about troubleshooting this, make sure you’re aware of the False positive in yesterday’s virus definitions.
https://blog.avast.com/2011/04/11/false-positive-issue-with-virus-defs-110411-1/
Update the virus definitions on that computer and see if you still have a problem.
If so, post the NON-WORKING URL of that site as Zyndstoff suggested.