McAfee SiteAdvisor his finally changed their rating on marxists.org after months (or maybe longer) of warning web users to refrain from using marxists.org. Within the past few days (not sure exactly when), all info on McAfee’s SiteAdvisor safety ratings now accurately reflects that marxists.org, a reputable Internet archive that has existed in various forms for around 15 years,  is officially a “good” site.  Their updated rating includes the following note:
Feedback from credible users suggests that this site is safe to use.

Still safe.   Way to eventually get it right, folks.  It doesn't explain the whole story, but it'll do.