What is Brontok? It’s a virus from the I-worm family. The virus is spread through the network so basically all the pc in a single network will be infected immediately once the infected pc connects into the network. What it does is creating new files which looked like a folder but its actually a .exe file. Unless you’ve enabled the view extensions in the folder options or else you won’t see the .exe extension of the file. The files are approximately 43.7Kb each and normally people will click to open them because they looked like a folder. So after you’ve open it, the virus will run each time during startup and keep on spreading and spreading… into the hard drives.
More troubles coming up. Normally when you click “Tools” in explorer, there’s a “folder options” underneath it. Once the pc is infected with the virus, the Folder Options will be missing, which disabled you to change the options to view the extension of the files. So when you see a new folder appeared from nowhere and you clicked to open it out of curiousity, the virus spread more again. Moreover, the virus disabled the registry edit where you will see this message “Registry edit is disabled by the administrator” everytime you try to edit the registry.
So how to clean the virus then? I found some solution from Symantec.
W32.Rontokbro@mm aka brontok.a
This article is based upon whatâ€™s written on Symantec Security Response. The original article can be found here
Read the original page to know much into the technical details. Iâ€™ll just extract the information on how to remove it, since u already know what it does and what name it carries.
The following instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.
1. Disable System Restore (Windows Me/XP)
2. Disable network folder sharing on any folder.
3. Update the virus definitions. Install one if you never had any. Norton and AVG already tested to be working. NOD32 might results to failure if the infections happen for the second time.
4. Boot the pc into safe-mode.
5. Run a full system scan and delete all the files detected. You may want to repeat this step a few times if thereâ€™s any file that failed to be removed.
6. After the files are deleted, restart the computer in Normal mode and proceed with the next section.
Warning messages may be displayed when the computer is restarted, since the threat may not be fully removed at this point. You can ignore these messages and click OK. These messages will not appear when the computer is restarted after the removal instructions have been fully completed. The messages displayed may be similar to the following:
Title: [FILE PATH]
Message body: Windows cannot find [FILE NAME]. Make sure you typed the name correctly, and then try again. To search for a file, click the Start button, and then click Search.
7. Use the Security Response “Tool to reset shell\open\command registry subkeys.”
1. To delete the value from the registry
Click Start > Run.
Note: If the registry editor fails to open the threat may have modified the registry to prevent access to the registry editor. Security Response has developed a tool to resolve this problem. Download and run this tool, and then continue with the removal.
Click Start, and then click Control Panel. (In Windows XP, switch to Classic View.)
In the Control Panel window, double click Scheduled Tasks.
Right click the task icon and select Properties from pop-up menu.
The properties of the task is displayed.
Delete the task if the contents of the Run text box in the task pane, matches the following:
Or just delete anything that you donâ€™t recognize or remember that you created. Just delete anything suspicious.
Ok now you are almost done. (The steps below are not covered by Symantec.)
Open your folder options (Start > Control Panel > Folder Options). If you failed to do so, follow this step:
Run you regedit.exe again and browse to this code:
Change the DWORD value to 00000000. You may need to restart your computer after that.
Now in the Folder Options, go to â€œViewâ€ tab, untick the option Hide extensions for known file types
Now browse carefully into you documents folder, since most of the time the worm will resides there. Try looking into you pictures folder (eg: My Pictures). If thereâ€™s a file that looks like a folder but ends something with .exe, delete it. Most of the time the name will be the duplication of the folder itself. (eg: D:\Documents\My Pictures\personal\personal.exe). The icon will be folder icon so be careful. If you happen to double click it, you will need to remove the virus again.
Check all folders in each drive just to make sure you are clean from it.
Sounds complicated right? I’ve uninstalled my ZoneAlarm Security Suite and installed AVG antivirus. Why I uninstalled it? ZA is almost useless in detecting worms where I found more than 20 files infected by scanning using AVG while ZA can’t find anything at all~! After cleaning, I installed another program, Ewido Anti-Malware, to check there’s any worm or spyware still available. This program is really good as it can detect spywares, worms, trojans, and even keyloggers. I found 160+ files infected after scanning the whole system in Safe Mode. Mostly are just trackers which is not really harmful.
The final steps I did are just following the steps above. In the end, I managed to enable the registry edit and also my folder options again. Now my pc is finally clean from the Brontoks~ I’ve killed you Brontoks!! Yippie!
Update 14 January 2007:
I found some alternative way to delete the virus. Not tested but it is being distributed by popular antivirus programs. Try using the removal tools from Bitdefender and Kaspersky
Download the tools and scan your computer with it. It will remove all the files infected with the Brontok virus. Good luck!~