I have been getting a few of these pop up this morning as well. Can only find one site that mentions anything related.
Hopefully McAfee can shed some light on what's going on.
Reputation - or 192.168.0.0
C:\Users\user\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.IE5\Y7P2R88S\addthis_widget.js - JS/Faceliker.ag - Critical - Trojan / Allow - True
We had the same issue starting around 7 am this morning, and lasting until early afternoon. McAfee confirmed the false positive and sent a new dat file which corrected the issue. Glad it was contained relatively quickly. Reach out directly to McAfee support, they probably need to send you a dat file, don't waste time here.