Avast blocking our site, lots of users complaining to us.

Avast Free Antivirus / Premium Security
1

Hi,

Last week we issued a new SSL certificate as the last one was going to expire soon. We are now getting dozens of emails a day from Avast users complaining how the site is blocked. It is due to the ‘HTTPS Scanning’ feature. Our certificate is valid and working well, but for some reason Avast is taking exception to it. We have reduced the number of ciphers used but nothing insane. I think it is especially todo with websockets but I don’t have a PC to hand to test this too much.

https://www.sharelatex.com
https://www.ssllabs.com/ssltest/analyze.html?d=www.sharelatex.com&s=50.116.54.17&latest

Can someone please advise on what can be done?

2

Report it here avast support https://support.avast.com

3

Blacklisted IP:
http://zulu.zscaler.com/submission/show/48c96b2d32c5c67b2501a1609884a524-1437664364
http://multirbl.valli.org/lookup/50.116.54.17.html

4

See…

https://www.virustotal.com/en/url/921eee33f6814705f03fcfbda71c72ccf29100f22e2c878d217d66ba6eceee0e/analysis/
http://quttera.com/detailed_report/www.sharelatex.com
https://sitecheck.sucuri.net/results/www.sharelatex.com
http://online.us.drweb.com/result/?url=http://sharelatex.com/
http://www.dnsinspect.com/sharelatex.com/1437671686
http://dnscheck.pingdom.com/?domain=sharelatex.com+&timestamp=1437672185&view

It appears to be “not” your domain but the IP address that is blacklisted.
Going by http://toolbar.netcraft.com/site_report/?url=sharelatex.com%2F+ I would strongly suggest you
set up a “sender policy framework” for your domain.

edit: I would suggest you follow the advice Pondus gave above.