Hello, I am actually a webmaster of the site of a company of formation at home, and since last Wednesday, our site is thrown rejected by Avast.
When we deactivate the Web shield, our site is again accessible.
Thank you for your answer Thomas
Well, you didn’t ask any question 
What’s the address of the site?
You get a virus detection on the main page directly?
I don’t get any such detection here…
What virus is reported?
Which is your firewall?
Does this blocking occur with any other site?
Is your avast updated?
No blocking for me with latest update, no suspicous code found. What exact message do you get?