Unfortunately at the present time, there is as usual no way to resolve this problem. Here is a article from the (Experts) at resolving such issues Locky Ransomware switches to THOR Extension after being a Bad Malware
As with any Security Vendor including McAfee this is a ever-revolving issue. Having said this (Bleeping Computer) is a reputable Site, with experts at anyone,s disposal to contact.
Your profile is indicative that you are a (Company) using a Corporate product? If indeed this is the case,it may be more appropiate for this thread to be moved to Corporate User Assistance
Please confirm if this indeed the case.