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Category: Malware

Type: Virus

Aliases: Worm.Win32.Viking.de, Win32/Viking.CH


Viking.DE, a variant of Viking, is a virus that it infects executable files on all available drives and has network spreading capabilities. The virus copies itself into the Windows directory and drops a DLL that downloads and runs files from a website. Viking.DE has a payload - it kills processes belonging to anti-virus and security software.


Disinfection of the Viking virus-worm should be performed as follows:
  • Disconnect a computer or local network from the Internet.
  • Disable network sharing or set strong passwords for all shares.
  • Select the "Disinfect Automatically" action for F-Secure Anti-Virus real-time scanners on all computers. With "Disinfect Automatically" selected, F-Secure Anti-Virus will disinfect files that a virus tries to infect over a network (if sharing was not disabled).
  • Scan all files on all drives on all computers and MANUALLY select the "Disinfect" action to disinfect all infected files and to rename the virus droppers. DO NOT select automatic disinfection option after the scan!
  • Restart all disinfected computers.
  • Scan all hard drives on disinfected computers again to make sure that no more infected files are left. If needed, repeat disinfection procedure.
  • Disinfect all infected computers connected on the network.
  • Enable network sharing, keep strong share passwords.
  • Reconnect the disinfected computer or local network to the Internet.

Please note that because of the "Worm." detection prefix F-Secure Anti-Virus will suggest to delete infected files, but DO NOT select the "Delete" option because this worm also has a viral component and you don't want to delete all infected files instead of disinfecting them. At the same time, the worm's dropper and downloader files should be deleted from a computer to prevent re-infection. See the names of the dropper and downloader files in the Details section.

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Technical Details

Installation to the System

The first time an infected file is run on a clean system, the virus activates and drops the following files into the main Windows directory:

  • Logo1_.exe
  • RichDll.dll

The .DLL component is then injected into the EXPLORER.EXE process. The virus also creates a subfolder named \UNINSTALL\ in the main Windows folder and then drops a file named RUNDL132.EXE at that location. The virus creates a startup value for that dropped file in Windows Registry:

  • [HKLM\Software\Microsoft\Windows\CurrentVersion\Run] load=%WinDir%\uninstall\rundl132.exe

Where %WinDir% represents the main Windows folder (usualy C:\Windows\).Viking.DE also adds the following registry entry as a part of its installation:

  • [HKLM\SOFTWARE\Soft\DownloadWWW] auto = "1"

The virus creates the following text files where it writes some information related to its activities:

  • C:\gamevir.txt
  • C:\log.txt
Infection of Files

Viking.DE is a prepending virus that searches for .EXE files on all available fixed hard drives and infects them by writing its body before the original file's body. In order for the host file to be run correctly, Viking.DE creates a backup copy of itself in the current directory as [filename].exe.exe and then drops and executes the original file as [filename].exe. After that, it deletes the uninfected original file and renames the backup file with the original filename. Viking.DE is able to do this with the help of a temporary batch file that it creates in the system's designated temporary folder as $$ad.bat. Viking.DE virus avoids infecting files with the following strings in their paths or filenames:

  • \Program Files\
  • Common Files
  • ComPlus Applications
  • Documents and Settings
  • InstallShield Installation Information
  • Internet Explorer
  • Messenger
  • Microsoft Frontpage
  • Microsoft Office
  • Movie Maker
  • MSN
  • MSN Gaming Zone
  • NetMeeting
  • Outlook Express
  • Recycled
  • system
  • System Volume Information
  • system32
  • windows
  • Windows Media Player
  • Windows NT
  • WindowsUpdate
  • winnt
Network Spreading Capabilities

The virus also attempts to propagate via network shares by copying itself to the following shared folders:

  • admin$
  • ipc$

- with the following accounts:

  • administrator
  • guest

As a part of the payload, the virus stops the following service:

  • "Kingsoft AntiVirus Service"

- and terminates the following processes related to several anti-virus products:

  • mcshield.exe
  • RavMon.exe
  • RavMonClass
  • Ravmond.EXE
  • regsvc.exe

The DLL component of Viking.DE virus attempts to download and execute files from Internet.

Description Created: 2006-12-14 07:27:00.0

Description Last Modified: 2006-12-14 17:53:07.0