boobooboo

I got a desktop here which i think has been infected by a rootkit. Now i reflashed BIOS and GPU and reinstalled windows7 pro. Right after install i copied the logs. In the logs of Microsoft-Windows-Security-Auditing i find this two user accounts (besides mine: JOHN-PC$) User Accounts WIN-2IGIUOJJOGU$ 37L4247F27-25$ I did not find a way to upload the .evtx file. So pasted the log here: http://pastebin.com/WkFTYGdU What are they and why are they here? Could this be rootkit activity adding a user?