Today received a report from user, computer is slow and seems have been infected with unknown virus or malware. No special symptoms except slow.
1. Check task manager and resource monitor
There is a process smss.exe which description is "Microsoft ? Console Based Script Host " using almost 75% CPU all the time.
From task manager, I found system was rebooted a couple of hours ago at very early morning and user was not around.
Also, no matter how you ended this process, it will come back in 10 seconds and take your CPU away and use about 4M your memory.