I would recommend you continue to use Malwarebytes as a second opinion on-demand scanner.No single product is 100% foolproof
and can prevent, detect and remove all threats at any given time. The security community is in a constant state of change as new infections appear and it takes time for them to be reported, samples collected, analyzed, and tested
by anti-virus/anti-malware researchers before they can add a new threat to database definitions. Malware writers have the advantage since no matter how hard security vendors attempt to stay on top of new threats, there is always a short time-frame in which a new malicious file goes undetected
and can infect a computer without detection. Just because one anti-virus or anti-malware scanner detected threats that another missed, does not mean its more effective. Every security vendor's lab and program scanning engine is different. Each has its own strengths and weaknesses and they often use a mix of technologies to detect and remove malware.
Security vendors use different scanning engines and different detection methods such as Heuristic Analysis
, Behavioral Analysis
and Signature file detection
(containing the binary patterns of known virus signatures
) which can account for discrepancies in scanning outcomes. Depending on how often the anti-virus or anti-malware database is updated can also account for differences in threat detections. Further, each vendor has its own definition (naming standards
) of what constitutes malware and scanning your computer using different criteria will yield different results. The fact that each program has its own definition files means that some malware may be picked up by one that could be missed by another.