:slight_smile: Hi :

  If "the thing" is covering up other files, then you MAY have
  a "rootkit" !? The best place to explore this possibility &
  get help would be the volunteer Rootkit Experts at :

  http://www.castlecops.com/f233-Rootkit_Revelations.html

  For detecting & quarantining "worms" I recommend 2
  possible program(s) NOT on Eddy's link, namely :
 1) FREE ver of "SUPERantispyware" from :
 www.superantispyware.com ;
 2) Ewido ( also FREE ) from :
 www.filehippo.com/download_ewido/?1208 .