Analysis by: Erika Bianca Mendoza
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Copies itself in all available physical drives, Propagates via removable drives

This worm may be unknowingly downloaded by a user while visiting malicious websites.

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

  TECHNICAL DETAILS

File Size: 659,456 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 25 Apr 2011

Arrival Details

This worm may be unknowingly downloaded by a user while visiting malicious websites.

Installation

This worm drops the following copies of itself into the affected system:

  • %system%\_svrhost.exe
  • %Program Files%\Common Files\Microsoft Shared\MSInfo\svrhost.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)

Autostart Technique

This worm adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\svrhost
ImagePath = %Program Files%\Common Files\Microsoft Shared\MSInfo\svrhost.exe

Propagation

This worm drops the following copies of itself in all physical and removable drives:

  • svrhost.exe

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

It modifies the contents of an existing AUTORUN.INF file to automatically execute its dropped copy. It does this by adding the following strings in the .INF file:

  • [AutoRun]
  • open=svrhost.exe
  • shellexecute=svrhost.exe
  • shell\Auto\command=svrhost.exe

  SOLUTION

Minimum Scan Engine: 8.900

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Restart in Safe Mode

[ Learn More ]

Step 3

Delete this registry key

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

 HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\svrhost

Step 4

Search and delete AUTORUN.INF files created by WORM_HUPIGON.DHE that contain these strings

[ Learn More ]
[AutoRun]
open=svrhost.exe
shellexecute=svrhost.exe
shell\Auto\command=svrhost.exe

Step 5

Scan your computer with your Trend Micro product to delete files detected as WORM_HUPIGON.DHE. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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