We’ve received several posts lately from concerned users who don’t know if their computers are infected or not by malware or spyware. The confusion seems to come from the scanner informing the user during the process of the scan that something has been detected. However, once the scan completes, the user is shown that nothing has been found on their system. So you’re asking, what’s the deal with that?

Well, this is brought about by some complexities in how we identify detections. Before we dive into the real issue, how about a few definitions…

latent detection – a potential detection on the machine that, by itself, is not enough to identify the machine as ‘infected’; eg. a file commonly associated with spyware is found on the system: think of something like spy.log being located

concrete detection – a positive detection on the machine; which by itself provides ‘concrete’ evidence to know the machine is ‘infected’

So, what is currently happening within the scanner is that we are seeing ‘latent’ detections on the system and immediately alerting you that they are there. However, when we get to the end of the scan, not enough items have been identified to come up with a ‘concrete’ detection. Because of this, we then state that nothing has been found.

We are currently working on getting this resolved for you in an upcoming release - but until then, there is no need to worry. Latent threats are not viewed as harmful to your machine - but rather could be remnants of something that was previously on your machine (but is no longer present). That means that the 'concrete' (or dangerous) part has already been removed - so sleep easy tonight :)

Look for an update to this in the near future!

-Bo Rohlfsen
Program Manager - Windows Live Safety Center