I use my Outlook (Microsoft) account to log into my main PC (Windows device link, Microsoft Store, etc.) But I use Windows Hello PIN to enter, not my typical Outlook password.
I also use the same Outlook account in a browser on my phone and an old notebook (both are over 15 years old and don't receive security updates). I have OneDrive and browser sync turned off, and remote desktop setting on my PC disabled.
If one of those older devices gets infected with malware (like a keylogger or spyware), can that somehow infect my main PC just because they’re all logged into the same Microsoft account?
I'm a noob when it comes to technology and security