What is it?
MS PowerToys Task Switcher
What does taskswitch.exe do?
This The cooler version of alt-tab which displays a little thumbnail of each window. You can download it and other useful utilites here:
OR Directly from us here
The original file from Microsoft gets placed in the C:WINDOWSSystem32 directory. if you find it anywhere else then you should be suspicious for sure.
You'll want to keep an eye on this google search for any known viruses. Currently there've been 0 reports.