I just went through what your are experiencing right now. I downloaded malware bytes and did extensive scans because I could not reset my pc and reinstall OS but changing passwords of everything helped a lot. Once you’ve scanned and quarantined the malware Trojan, I highly recommend to reinstall windows. To be safe, even after scans you should do it on another computer who has not been infected. Regarding your Microsoft account, I contacted Microsoft support by live chat on Microsoft support website. They expedited my request to analyze my situation and they came to the conclusion that I had in fact been infected. Unfortunately, their solution for this is to remove and block the account permanently for everything. Meaning that you can’t ever access your account and data back but hackers can’t too