|To add to #1:|
Follow the sequence in the exact order including MalwareBytes which you've already run. Before running MalwareBytes go to "Settings > Detection and Protection" and ensure there is a check mark in "Scan for rootkits" (it only adds about 1 minute to its running time).
Just for info, the best time to run CCleaner is immediately after you "suspect" something is awry as it clears out anything nasty that has just arrived in temporary internet files. After that is mostly far too late as the thing has already taken root.
Always pop back and let us know the outcome - thanks
message edited by Derek