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: 2006-12-18

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 password stealing trojans.

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Malware Proliferation

On execution, it copies itself in %Windir%\Uninstall as rundl132.exe and adds a registry entry to activate itself on reboot.

  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

It also creates the following registry entries:


It drops a file named richdll.dll (detected as W32/HLLP.Philis.dll) in %WinDir%. It then injects this dll into the Explorer.exe shell process. This dll is responsible for downloading other password stealing trojans such as PWS-LegMir from the following locations:


W32/ searches for executable files and prepends its viral code to target files. It adds its 58KB code in front of the original file, so whenever that file is executed the virus is also executed.

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

  • Presence of %WinDir%\RichDll.dll
  • Pesence of registry entries as described
  • Presence of files named _desktop.ini
    • These files have the system (S) and hidden (H) attributes set and 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.

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.