How to remove BiFrost virus svchost.exe

BiFrost virus svchost.exe

Last Updated on Friday, 02 April 2010 07:43 Thursday, 24 December 2009 14:58

The file name svchost.exe has appeared in several virus analysis report. You can see one on this link

I will include info of other variations of this viruses and when they are identified. Please see the "Delete Files" for other variations

svchost.exe is a common name in windows Task Manager. At any given time you should be able to see several svchost.exe processes running in the task manager. The legitimate svchost.exe file is located at C:\Windows\System32 folder.

This installer is identified as a backdoor Trojan Bifrose or BiFrost. It connects to remote hosts. It can download harmful files from the internet. A good firewall can detect harmful activities and prevent them. Some good freeware are ZoneAlarm Free Firewall, and Comodo Internet Security Free Edition (you can choose to install just the firewall from their security suite)

It infects Internet explorer browser. It attaches a keylogger with Internet Explorer. That will steal your user ID and passwords. So do not use Internet explorer until the virus is removed.

It creates the file svchost.exe on the infected computer at the location mentioned below.

There are several variations in the EXE file names used by this virus. I have grouped them together in BiFrost Family category

Statutory Warning: It is possible that some legitimate application may be using the same name as that of the virus. Use Windows Defender or SysInternal Process Explorer to differentiate between them.

Boot in safe mode

Sometimes you can not delete a file. You should boot in safe mode and then try to delete it.

How to boot in safe in windows XP

How to boot in safe mode in windows Vista

View Hidden Files

You need to enable to view hidden files and folders before searching.

How to Enable to View Hidden Files and Folders in Windows XP
- How to Enable to View Hidden Files and Folders in Windows Vista

Remove Processes from Task Manager

Press Ctrl Alt Del keys to open the Task Manager. Select Processes tab. You will see a list. Look for the name svchost.exe in it. Select if found and press the End Process button. It will ask for your confirmation to end that process. Select Yes. You can end one process at a time.

You can find out if a process in Task Manager is good or bad by using Windows Defender. It shows the path of a process and its publisher. Harmful processes may be shown under Unknown Publisher in windows defender.

How to use Windows Defender in windows XP

How to use Windows Defender in windows Vista

Or you can use Sysinternal's Process Explorer.

How to use Sysinternal's Process Explorer

Removing entry from windows startup

The system configuration can be started in xp and in vista by typing msconfig in the run box/ start menu search box. In xp by clicking on Start > run . The windows startup is reversible. You can check / uncheck any entry from windows startup any number of times.

Open system configuration window. Click on the Startup tab. You will see a list all the programs that are scheduled to start with windows. Expand the middle column using your mouse pointer. That will show you the full path of the program. Locate and uncheck "svchost.exe" (also look for any other suspicious names) Press Apply , Press Close/Ok , Select "restart" at the next prompt.

Deleting files

The computer will restart now. After restarting use the windows search utility. Search for "svchost.exe" and other names listed below. Delete the folders and files found in the search. Boot in safe mode or boot in the dos prompt if needed.

Variation 1

These are the files created by this virus

C:\Program Files\microsoft\svchost.exe
C:\Program Files\microsoft\keys.dat
C:\Documents and Settings\[UserName]\Application Data\germany.dat
C:\Documents and Settings\[UserName]\Application Data\Microsoft\keys.dat
C:\Documents and Settings\[UserName]\Application Data\Microsoft\svchost.exe
%Temp%\1.exe
%Temp%\2.exe

and these folders are created by this virus

C:\Program Files\microsoft(This is a legitimate folder found on most of the windows computers. So do not delete the folder, but delete the files inside that folder keys.dat, svchost.exe) Variation 2 see report
C:\AUTORUN.INF
C:\Windows\SVCHOST.EXE
C:\Windows\system\MSMOUSE.DLL
C:\Windows\system\SVCHOST.EXE(It is a point to be observed that there is a legitimate file C:\Windows\System32\SVCHOST.EXE, but C:\Windows\system\SVCHOST.EXE and C:\Windows\SVCHOST.EXE are not a legitimate files) Variation 3 see report FilesC:\Documents and Settings\[UserName]\Application Data\logs.dat
C:\Windows\System32\Services\svchost.exe
%Temp%\csrss.exe
%Temp%\ewUV4DJTQ6.exe
%Temp%\firefox.exe
%Temp%\Hackhoundserver.exe
%Temp%\iExplorer.exe
%Temp%\iS 6 Legends.exe
%Temp%\iStealer.exe
%Temp%\UuU.uUu
%Temp%\XxX.xXxFolderC:\Windows\System32\Services Variation 4 see report FilesC:\Documents and Settings\[UserName]\Application Data\addon.dat
C:\Documents and Settings\[UserName]\Application Data\awServ\svchost.exe
C:\Windows\System32\awServ\svchost.exe
C:\Windows\System32\awServ\klog.dat
%Temp%\1.scr
FolderC:\Documents and Settings\[UserName]\Application Data\awServ
C:\Windows\System32\awServVariation 5 see report Files
C:\Documents and Settings\[UserName]\Application Data\addon.dat
C:\Windows\ssystem32\klog.dat
C:\Windows\ssystem32\svchost.exe
Folder
C:\Windows\ssystem32
Variation 6 see report Files
C:\Documents and Settings\[UserName]\Application Data\addons.dat
C:\Program Files\resaux\logg.dat
C:\Program Files\resaux\svchost.exe
Folders
C:\Program Files\resauxVariation 7 see report Files
C:\Documents and Settings\[UserName]\Application Data\Microsoft\Crypto\RSA\S-1-5-21-606747145-764733703-839522115-1003\699c4b9cdebca7aaea5193cae8a50098_a7bcc1a4-f7a4-4502-8650-8579e607f7f7
C:\Windows\System32\CTF\klog.dat
C:\Windows\System32\CTF\svchost.exe
Folders
C:\Windows\System32\CTF
Registry KeysSome of the registry keys will be automatically removed if you run Registry menu of CCleaner.

Using CCleaner

You can easily remove the files in the temp folder by running CCleaner. You can set CCleaner to run automatically each time the computer starts.

Do not forget to run CCleaner > Registry menu to remove the obsolete registry entries.