potential rootkit - Win32:Rootkit-gen[Rtk]

Viruses and worms
1

Hello everyone,

My avast! displays a “threat has been detected” message two or three times every day. The threat always refers to the same file, C:\WINDOWS\system32\eobij.fre

Avast! says the threat was detected when creating or modifying the file, by process ID 4 (which is ‘System’) and proceeds to move the file to the chest. The threat is reported as Win32:Rootkit-gen[Rtk]

Is it a false positive? Is this a real rootkit? If so, how can I remove it? What do you advice me to do?
Thank you very much.

2

Please attach your logs. (AdwCleaner, MBAM, OTL and aswMBR…!!)
Instructions: http://forum.avast.com/index.php?topic=53253.0

3

also upload and test the file at www.virustotal.com
post link to scan result here

alternative: www.metascan-online.com / www.jotti.org

4

Thank you for your reply. I am attatching them to this post.

I don’t know how. The file is automatically sent to the Virus Chest, and can no longer be found at the reported location (c:/windows/system32/)

5

Here is the last log, I could only attatch four files.

6

Looks like Avast killed it… How is the computer behaving ?

Warning This fix is only relevant for this system and no other, using on another computer may cause problems

Be advised that when the fix commences it will shut down all running processes and you may lose the desktop and icons, they will return on reboot

Run OTL

[*]Under the Custom Scans/Fixes box at the bottom, paste in the following

https://dl.dropbox.com/u/73555776/OTL_Fix.GIF


:Commands
[CREATERESTOREPOINT]

:Files
H:\WINDOWS\tasks\At*.job

:Commands
[resethosts]
[emptytemp]
[Reboot]

[*]Then click the Run Fix button at the top
[*]Let the program run unhindered, reboot the PC when it is done
[*]Open OTL again and click the Quick Scan button. Post the log it produces in your next reply.

7

I have not received any new notification, so it seems the treat has been removed. However, I will wait one or two days to be sure. I’ll let you know.
Thank you very much!

8

Unfortunately, the “rootkit detected” has popped up again this morning.

I have gone to the Virus Chest and sent the file to lab.

9

Was it the same file ?

Download and Install Combofix

Download ComboFix from one of the following locations:
Link 1
Link 2

VERY IMPORTANT !!! Save ComboFix.exe to your Desktop

  • IMPORTANT - Disable your AntiVirus and AntiSpyware applications, usually via a right click on the System Tray icon. They may otherwise interfere with our tools. If you have difficulty properly disabling your protective programs, refer to this link here

[*]Double click on ComboFix.exe & follow the prompts.
[*]Accept the disclaimer and allow to update if it asks

http://img.photobucket.com/albums/v706/ried7/NSIS_disclaimer_ENG.png

http://img.photobucket.com/albums/v706/ried7/NSIS_extraction.png

[*]When finished, it shall produce a log for you.
[*]Please include the C:\ComboFix.txt in your next reply.

Notes:

  1. Do not mouse-click Combofix’s window while it is running. That may cause it to stall.
  2. Do not “re-run” Combofix. If you have a problem, reply back for further instructions.
  3. If after the reboot you get errors about programmes being marked for deletion then reboot, that will cure it.

Please make sure you include the combo fix log in your next reply as well as describe how your computer is running now

10

Yes, it is the same exact file every time.

I jusr run ComboFix, and I am attatching the log. I’ll have to wait for another whole day, because the message only appears about two times a day.
Thank you!

11

I forgot to attatch the file (d’oh!)

12

Threat detected again, right now.

I’m starting to think this file is regenerated by the System process from time to time, and it might be a false positive.
However, I didn’t get this message until a couple of weeks back.

13

Did you create these vbs scripts at all ?

[HKEY_LOCAL_MACHINE\software\microsoft\windows\currentversion\group policy\state\S-1-5-21-3682870541-922198670-637463191-1520\Scripts\Logon\0\0] "Script"=Mapping_W.vbs . [HKEY_LOCAL_MACHINE\software\microsoft\windows\currentversion\group policy\state\S-1-5-21-3682870541-922198670-637463191-1520\Scripts\Logon\0\1] "Script"=Mapping_S.vbs . [HKEY_LOCAL_MACHINE\software\microsoft\windows\currentversion\group policy\state\S-1-5-21-3682870541-922198670-637463191-1520\Scripts\Logon\0\2] "Script"=Mapping_R.vbs . [HKEY_LOCAL_MACHINE\software\microsoft\windows\currentversion\group policy\state\S-1-5-21-3682870541-922198670-637463191-1520\Scripts\Logon\0\3] "Script"=HrdWrInv.vbs . [HKEY_LOCAL_MACHINE\software\microsoft\windows\currentversion\group policy\state\S-1-5-21-3682870541-922198670-637463191-1520\Scripts\Logon\0\4] "Script"=SftWrInv.vbs

Could you run a fresh OTL scan please and ensure all users is selected