can you think of a time when anyone saw something that looked like this:
Address: CBbU3826CChKYTxfhNZRqvCzMGUtk6mi9U
Privkey: 6CxUCM6K7eSj47jur8ruZsgExEzqi47cZP4VoBHAfTeVcEcg44N

because if they did you coins are long gone.

or can you think of any popups or installers that were used recently for programs you were unsure about or could not stop form installing.

crypto is terribly full of assholes who would do anything malicious to grab coins. even people who are top at security in their mind have been ripped off. at this point crypto is very very hard to secure and maintain if your just a casual computer user.

I would suggest if you have any other coins on that computer in any wallets you move them up to an exchange while you investigate to see what security leak you have whether its a keylogger, a virus, or you giving away the private key and someone spending with it.