I had a problem with hard drive filling up .I found program (pup) c:/users/user/appdata/local/browser helper to be the culpret .it had a txt file which was 333gb big already .i deleted it and all is fine
I recommend you perform a full malware scan, inside safe mode if possible. Behavior like that especially in the appdata folder is typical for malware. The name browser helper also sounds highly suspicious.