malware message when I start firefox, from ocsp.comodoca?

When I start the browser (firefox variant,palemoon), I receive a ‘threat has been detected’ message from avast, just as the browser directs me automatically to

ocsp.comodoca.com, ie ‘connect to:178.255.83.1’, which seems to be a UK ip

Is this an malicious site, or official comodo address? It kept happening a few minutes ago, but is no longer doing so.
I’m using Comodo as my firewall. I know this is not a directly related to Comodo’s antivirus software, but I would like to find out if it’s a malicious address, since it obviously points towards Comodo. Nothing came up in my last malware scan. Thanks for any info. Is it a browser issue?

Update- I’ve just installed superantispyware and I can see it must be an official comodo address - info on everything I install is being sent to comodo for analysis and avast deems this as suspect. The warning is coming up every 10 seconds at the moment, the process is now superantispyware, the IP address is the same comodo one as before, still reported as malware :slight_smile:
https://forums.comodo.com/install-setup-configuration-help-cis-b137.0/-t101981.0.html

It is a look up to see if certificates are revoked or not: Online Certificate Status Protocol - Wikipedia .

Avast flagging it as threat is a false positive. They need to fix it.