W32/HLLP.Philis.hc

This page shows details and results of our analysis on the malware W32/HLLP.Philis.hc

Overview

W32/HLLP.Philis.hc is a file infecting virus. It searches for executable files on the infected machine to prepend its viral code and due to a bug in virus code it may corrupt the executables. It is also responsible for dropping a .DLL file, which downloads password stealing trojans.


Minimum Engine

5600.1067

File Length

63,556 bytes

Description Added

2007-03-02

Description Modified

2007-03-14

Malware Proliferation

Characteristics

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

  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\ Run\load = "%WinDir%\uninstall\rundl132.exe"

It also creates the following registry entries:

  •  HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DownloadManager
  •  HKEY_LOCAL_MACHINE\SOFTWARE\Soft\DownloadWWW\auto: "49"

It drops a file named Richdll.dll (detected as W32/HLLP.Philis.dll) in %WinDir%.
It then injects this dll in processes Explorer.exe and IExplor.exe. This dll is responsible for opening a backdoor and also downloading other password stealing trojans from the following locations:

  • http://[removed].54699.com 

W32/HLLP.Philis.hc searches for executable files and prepends its viral code to target files.
It prepends itself to the original .EXE file, so whenever that file is executed the virus is also executed. The prepending virus code is written using Borland Delphi.

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 and 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.

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.

The virus attempts to terminate the processes of several security products if running on the affected system.

Symptoms

  • 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
  • Few executables may not run properly
  • Increase in disk activity (read and write)
  • HTTP network traffic to the aforementioned web address

Method of Infection

W32/HLLP.Philis.hc 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.

Removal

All Users:
Use current engine and DAT files for detection and removal.

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).

But in some particular cases, the following steps need to be taken.

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.

Variants