What I tried: full scan (both in Failsafe-mode and in Windows) with everything I've got - Malwarebytes Premium, Zone Alarm ES, HitmanPro, Win Defender and Eset (onlinescanner), and they all came up clean, as usual. All security software running in this machine, as well as Windows Update, are upp to date. I have therefore good reason to suspect a malware infection of some kind. Most noticeable is a significant drop in transfer speed, unexpected delays, 5-10 seconds long 'black-outs' where the computer refuse to take input of any kind (including CTRL-ALT-DEL), and more. However, I used their ONLINE SCANNER once for a while ago, and is now experiancing an array of problems ever since.
I have NO Kaspersky software installed om this machine, never had.