You can probably monitor your internet traffic and see what's up. Are packet sniffer programs still a thing?? I used to store my files on an external drive (with physical kill switch) so even if someone got access, most of the data was offline 99% of the time.
@previous (FuckAlms !vX8K53rFBI)
The correct answer. Full wipe and start over, Linux while you're at it.
(Edited 1 minute later.)