I believe my parents computer was infected after she took a call from someone pretending to be "microsoft." She even went to the extreme of giving her bank info over the phone and the next day I found out and asked her what the he** she was thinking, then told her to go to her bank and she was able to change her card number, get a new account number, and all new checks issued out as well and nothing was taken out of her account. The guy installed two programs called "CCleaner and Malwarbytes," now whether they were the actual programs or masked, I immediately removed them, but then I decided just to backup her turbotax forms and do a format. After running the format, I activated my 60 days with Norton and ran a full system scan and nothing was detected except 5 tracking cookies that were removed and with the legit Malwarbytes I ran a full system scan and nothing was detected there either. I've heard that Malware can survive a format and am wondering what ways I am sure that her computer is 100% clean if that is even possible, before she can trust using passwords and stuff on her computer.
Thanks in advance.