Plex media server.exe is trying to access your login info in Firefox?

[Ridley]

Feb 13, 2022 22:23:36.764 [24564] DEBUG - Request: [127.0.0.1:57400 (WAN)] PUT /:/prefs?sendCrashReports=0&PushNotificationsEnabled=0&logDebug=0&LogVerbose=0 (24 live) TLS Signed-in Token (3pwood)

It appears that a remote attacker sent a request to PMS telling it to disable as much logging as possible (using a valid auth token for your account). Then, while logging was reduced, it attempted to use PMS to scan your local filesystem, thus triggering the Avast warning. You should assume that at least one token belonging to your account is compromised. Follow these steps:

@Ridley

If you encounter strong signs of unauthorized access to your server, go to Account Settings on app.plex.tv and reset your password, making sure to check the “ Sign out connected devices after password change ” box. You should use a password manager (there’s one built into most modern web browsers, and third-party options are also available) to generate a random password, rather than creating a memorable (and potentially guessable) one. Always use a unique password; never reuse the same password across several services.

EDIT: Further investigation indicated no signs of local-machine compromise; section removed.