I can add to this...way back when I was infected by a keylogger, the good people on this forum had me install malwarebytes, which I did. A coupla days later, it was deleted from my computer...re-installed it, coupla days later, disappeared again. 3 times in all. Was recommended I remove AdAware, as it was likely the culprit, and sure enough...(as to uninstalling AdAware, THAT was a whole new drama in itself! Just didn't want to go...)
Regards,
Shax