
Quote: Originally Posted by
jimbo45
Suppose you find out AFTER a scan that your computer has a Virus -- well other than that you should wipe your computer, re-install the O/S and data either from scratch or restore from a known CLEAN image backup you can't possibly know how long its been there or what its actually done -- so I go back to the main point ANY AV software that just tells you AFTER you have been infected is a WASTE OF TIME and NOT WORTH INSTALLING.
Hi, jimbo45.
One point to consider is that vendors have different sources for adding to detection. Thus, particularly when it is a new malware variant, it may not have been added to detection at the time the computer became infected. It was subsequently found because the definitions were updated to include the variant.
Note: The above is not meant to start a discussion on heuristics, merely an explanation on how malware can be missed at one point by a program and subsequently found in a scan.