Since about Oct. 26 every time I search with Firefox (default is Google), MalwareBytes blocks access to website mps.eanswers.com, on port 51600, 52204, and 52248, most recently. If I search from within Outlook (using Bing), the search somehow gets redirected to Firefox. The pop-up error message indicates varying IP address varies. I'm using Malware Premium 3.61. However, MalwareBytes does not detect any malware on my system in full system scans. I'm also using Norton Internet Security, which comes with my Comcast service, and it also doesn't detect any malware.
Searches using Edge/Bing are OK.
At first I thought that some software I installed was the source of the malware, but I installed the same software on two different systems, and only one system is infected.
Both systems are running Windows 10 Pro 64, fully patched up. Firefox is 64-bit , latest version.
Instead of doing a shotgun approach, how should I proceed methodically and efficiently to track down this problem? I have reasonable technical skills.