Thanks for the response,
@cmkelley.
I'd read that post you linked before asking the question, and had tried following the "tutorial" through amtm's menu, instead of commands. However, the debug didn't provide me with "DST=" or anything like it when testing the blocked connection.
Because I didn't have an IP to test, I couldn't use AlienVault's search tool. Since the two websites I mentioned were listed under "associated domains" (and I regularly browse them), I ended up whitelisting the domains themselves.
I didn't know about the hosting provider issue that you mentioned, and was afraid those domains had been compromised, somehow. I assume other bad actors are hosted under the same blocked IP, so what I did - whitelisting the specific domains, rather than the IP - would be the best option in cases like this?