My laptop (Lenovo Z500, Windows 8) has been acting slightly sluggishly over the past month. Videos stutter occasionally, scrolling and typing speeds aren't as smooth as they used to be and it takes slightly longer to start up. I ran virus scans (using Malwarebytes Anti-Malware and Windows Defender) when I felt like I might have an infection but at first found nothing, until one day MBAM picked up a piece of malware (PUP.Optional.Installex). Looking at the file it had apparently been downloaded two weeks before detection, even though I had scanned several times since then and found nothing.
I'm not sure if I'm being paranoid but I want to take care of this laptop as it's only a few months old, and given that it took two weeks to locate malware on my system I don't know whether to trust that the current scans are right that my laptop is clean. Is it possible to check whether I still have an infection?
(The full extension of the virus was ".exe.part"; I'm told that ".part" means that Firefox only partially downloaded the file. Does this mean that the virus was itself corrupt or incomplete, and so wasn't functioning at all?)
Edited by Osprey95, 14 August 2013 - 09:28 AM.