Analysis by: jont
 PLATFORM:

Windows 2000, XP, Server 2003

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This worm drops copies of itself into all the physical drives of an affected system. 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: Varies
File Type: PE
File Compression: Aspack
Memory Resident: No
Initial Samples Received Date: 18 Nov 2010

Installation

This worm drops the following files:

  • %System%\jpking.exe - copy of itself
  • %System%\jpking0.dll - detected as Cryp_OLGM-41
  • %User Profile%\Local Settings\Temp\rbking.exe - copy of itself
  • %User Profile%\Local Settings\Temp\rbking0.dll - detected as Cryp_OLGM-41

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.. %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
king_rb = "%User Profile%\Local Settings\Temp\rbking.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
king_jp = "%System%\jpking.exe"

Other System Modifications

This worm adds the following registry entries as part of its installation routine:

HKEY_CLASSES_ROOT\CLSID\MADOWN
urlinfo = "tfsxr.q"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\MADOWN
urlinfo = "tfsxr.q"

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = 2

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = 0

(Note: The default value data of the said registry entry is 1.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\Hidden\
SHOWALL
CheckedValue = 0

(Note: The default value data of the said registry entry is 1.)

Propagation

This worm drops copies of itself into all the physical drives of an affected system.

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

The said .INF file contains the following strings:

[AutoRun]
open=rj1.exe
shell\open\Command=rj1.exe

Download Routine

This worm downloads an updated copy of itself from the following website(s):

  • http://www.{BLOCKED}wf.com/1rb/ar1.rar

  SOLUTION

Minimum Scan Engine: 8.900
FIRST VSAPI PATTERN FILE: 7.674.02
FIRST VSAPI PATTERN DATE: 03 Dec 2010

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

Remove malware files dropped/downloaded by WORM_GAMETHI.FAX

    • Cryp_OLGM-41

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

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.

 
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\
    • MADOWN
  • In HKEY_CLASSES_ROOT\CLSID\
    • MADOWN

Step 5

Delete this registry value

[ 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.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • king_rb = %User Profile%\Local Settings\Temp\rbking.exe
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • king_jp = %System%\jpking.exe

Step 6

Restore this modified registry value

[ 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.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: Hidden = 2
      To: Hidden = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: ShowSuperHidden = 0
      To: ShowSuperHidden = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
    • From: CheckedValue = 0
      To: CheckedValue = 1

Step 7

Search and delete AUTORUN.INF files created by WORM_GAMETHI.FAX that contain these strings

[ Learn More ]
 [AutoRun]
open=rj1.exe
shell\open\Command=rj1.exe

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_GAMETHI.FAX. 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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