This page shows details and results of our analysis on the malware W32/

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Threat Detail

  • Malware Type: Virus
  • Malware Sub-type: Parasitic
  • Protection Added: 2006-11-17

W32/ is a file infecting virus. It searches for executable files on the infected machine to prepend its viral code. It is also responsible for dropping a .DLL file, which downloads a password stealing trojan from a website.

Minimum Engine


File Length

60,140 bytes

Description Added


Description Modified


Malware Proliferation

-- Update November 17, 2006 --
The 4899 DAT files are being released early as there is concern that this thread will spread globally.  The web site hosting malware downloaded by this threat also contains Exploit-MS06-014 to automatically download and installs this virus on vulnerable systems.

On execution, this variant copies itself into %WinDir%\Uninstall folder as rundl132.exe and adds a load registry entry to activate itself on reboot. It also creates the following registry entries:

  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DownloadManager
  • HKEY_LOCAL_MACHINE\SOFTWARE\Soft\DownloadWWW\auto: "1"

It drops a .DLL file named RichDll.dll (detected as W32/HLLP.Philis.dll since the 4896 DATs) in %WinDir%. It then injects this dll into processes Explorer.exe and IExplore.exe. This dll is responsible for downloading the PWS-Lineage password stealing trojan from the following location:


W32/ searches for executable files and prepends its viral code to target files.

The virus creates files with the name "_desktop.ini" in every folder that it visits while looking for executable files to infect. This is created as a hidden system file and contains the date on which virus was executed to visit the folder in which the file resides. The date is shown in yyyy/mm/dd format.

The virus tries to spread via existing network shares. It searches for all active machines within the subnet. When it finds an active machine it sends an ICMP ping request and waits for a response. 
After getting the ping response it tries to access the ADMIN$, IPC$ and any other shares that might exist on the machine.

If the virus is able to access a shared resource, it first copies "_desktop.ini" to the root of the share to mark the share as visited and then infects executables present in the share.

While infecting executables via a network share the virus does not limit itself to infecting specific file names as mentioned above. In the case of a shared printer, the viruses' infection routine effectively creates printer job to print the date as contained in "_desktop.ini" file that the virus tries to copy.

  • Presence of %WinDir%\RichDll.dll
  • Presence of registry entries as described
  • Presence of files named _desktop.ini in many folders.
    • These files have the system (S) and hidden (H) attributes set
    • These files are detected as W32/HLLP.Philis.ini
  • Increase in size of EXE files
  • Increase in disk activity (read and write)
  • HTTP network traffic to the aforementioned web address
  • W32/ is a file infecting virus. Infection starts with manual execution of the binary. For spreading, the virus also relies on improperly configured/protected (open) shared drives.

    All Users:

    Please use the following instructions for all supported versions of Windows to remove threats and other potential risks:

    1.Disable System Restore .

    2.Update to current engine and DAT files for detection and removal.

    3.Run a complete system scan.

    Modifications made to the system Registry and/or INI files for the purposes of hooking system startup, will be successfully removed if cleaning with the recommended engine and DAT combination (or higher).

    1. Please go to the Microsoft Recovery Console and restore a clean MBR.

    On windows XP:

    Insert the Windows XP CD into the CD-ROM drive and restart the computer.
    When the "Welcome to Setup" screen appears, press R to start the Recovery Console.
    Select the Windows installation that is compromised and provide the administrator password
    Issue 'fixmbr' command to restore the Master Boot Record
    Follow onscreen instructions
    Reset and remove the CD from CD-ROM drive.

    On Windows Vista and 7:

    Insert the Windows CD into the CD-ROM drive and restart the computer.
    Click on "Repair Your Computer"
    When the System Recovery Options dialog comes up, choose the Command Prompt.
    Issue 'bootrec /fixmbr' command to restore the Master Boot Record
    Follow onscreen instructions
    Reset and remove the CD from CD-ROM drive.