How do I remove Time Machine Threats??

I am a new user to Sophos.  I scanned my iMac's hard drive, it discovered a few things and it removed them.

Then, I scanned my Time Machine connected disk.  22 Threats were identified.  All 22 say the cleanup failed.  When I look at the details, some of the threats appear only once, others in multiple backup sets.  The problem is Clean Up Threat is greyed out, Reveal in Finder doesn't seem to do anything, and Reveal in Finder doesn'gt seem to do anything.  In addition, in the Show Details section, where it lists the path and file name, because of the length of the path, I can't see where the threat file actually resides.  Where does the quarantine manager file live?  If the cleanup failed, what are my alternatives.  

Also, these are Time Machine backup files, make this issue more problematic?   And, in looking at the detail on a number of these threats, the threat link said that the affected operating system was Windows.  Does this make this a non-issue on a Mac?

Thanks in advance for any assistance.