@shortridge Years ago a friend walked into my office in a panic. A hacker had taken over her machine and kept inputting random words into whatever document or file was open.
The hacker would go on rants about the UN and other topics, just filling up her documents. It persisted across reboots, but no malware could be found on the machine.
Security guy to the rescue! We took a look at the system and eventually found the issue: MS Word's speech to text was on, with the gain turned way up!