Why can Windows Security Essentials find viruses and malware that Webroot does not detect?

@ wrote:

Multiple, numerous full scans by Webroot indicated no concerns. WTH?!?

@,
 
From the screenshot you provided, those are all old Java exploits. Webroot SecureAnywhere does not detect the exploits themselves, but will detect any executable payloads loaded by those exploits.
 
You may also want to note that all of those exploits appear to be from 2012 and older, and the one that is listed was found deep within a backup of yours from 2010. Those exploits were likely removed years ago and just happen to be in some old backups.
 
-Dan