WORM_GAMETHI.GGN

 Analysis by: Cris Nowell Pantanilla
 Modified by: Michael Cabel

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Copies itself in all available physical drives, Propagates via removable drives

This worm arrives via removable drives. It may be downloaded by other malware/grayware/spyware from remote sites.

It modifies registry entries to hide files with System and Read-only attributes.

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

It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size:

Varies

File Type:

PE

Memory Resident:

Yes

Initial Samples Received Date:

07 Oct 2011

Payload:

Downloads files, Steals information, Terminates processes

Arrival Details

This worm arrives via removable drives.

It may be downloaded by other malware/grayware/spyware from remote sites.

Installation

This worm drops the following component file(s):

  • %System%\jpking0.dll - also detected as WORM_GAMETHI.GGN
  • %User Temp%\4tddfwq0.dll - also detected as WORM_GAMETHI.GGN

(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 Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)

It drops the following copies of itself into the affected system:

  • %System%\jpking.exe
  • %User Temp%\xvassdf.exe

(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 Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp 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_jp = "%System%\jpking.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
54dfsger = "%User Temp%\xvassdf.exe"

Other System Modifications

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

HKEY_CLASSES_ROOT\CLSID\MADOWN

It modifies the following registry entries to hide files with System and Read-only attributes:

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 the following copy of itself in all physical and removable drives:

  • puia6h.exe

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=puia6h.exe
shell\open\Command=puia6h.exe

Process Termination

This worm terminates the following processes if found running in the affected system's memory:

  • ALUSCHEDULERSVC.EXE
  • ASHDISP.EXE
  • AVGNT.EXE
  • AVGRSX.EXE
  • AVP.EXE
  • AYAGENT.AYE
  • AYUpdate.aye
  • CCSVCHST.EXE
  • EKRN.EXE
  • SfFnUp.exe
  • UFSEAGNT.EXE
  • UfUpdUi.exe
  • Update.exe
  • VCRMON.EXE
  • VSTSKMGR.EXE
  • avast.setup
  • avgupd.exe
  • eguiEmon.dll
  • eguiEpfw.dll
  • ekrnEmon.dll
  • ekrnEpfw.dll
  • luall.exe
  • mcupdate.exe
  • preupd.exe
  • prupdate.ppl
  • setup.ovr
  • update.exe
  • updater.dll
  • vsupdate.dll

Download Routine

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

  • http://www.{BLOCKED}d3.com/1rb/ar1.rar
  • http://www.{BLOCKED}os.com/1rb/ar.rar
  • http://www.{BLOCKED}os.com/1rb/ar1.rar
  • http://www.{BLOCKED}js.com/1rb/ar.rar
  • http://www.{BLOCKED}js.com/1rb/ar1.rar

Other Details

This worm deletes the initially executed copy of itself

NOTES:

It injects its dropped .DLL files to all running processes to renamin memory resident.

Information Theft Routine

This spyware monitors the following URLs in an attempt to steal user credentials:

  • www.arad.jp
  • arad.hangame.co.jp
  • member.gungho.jp

It attempts to steal login information, such as user names and passwords, from the following processes related to popular online games:

  • ARAD.exe
  • Atlantica.exe
  • cabalmain.exe
  • coc.exe
  • maplestory.exe
  • pol.exe
  • Ragexe.exe
  • red stone.exe

It also attempts to steal information from the following file if present on the affected system:

  • aaa.dat

It attempts to connect to any of the following remote sites to send the gathered information:

  • {BLOCKED}.{BLOCKED}.95.140
  • {BLOCKED}.{BLOCKED}.95.146
  • {BLOCKED}.{BLOCKED}.95.138
  • {BLOCKED}.{BLOCKED}.95.144
  • {BLOCKED}.{BLOCKED}.95.148
  • {BLOCKED}.{BLOCKED}.95.134
  • {BLOCKED}.{BLOCKED}.95.142
  • {BLOCKED}.{BLOCKED}.95.150
  • {BLOCKED}.{BLOCKED}.95.136
  • {BLOCKED}.{BLOCKED}.95.130
  • {BLOCKED}.{BLOCKED}.95.128
  • {BLOCKED}.{BLOCKED}.95.132
  • {BLOCKED}.{BLOCKED}.95.152
  • {BLOCKED}.{BLOCKED}.95.154
  • {BLOCKED}.{BLOCKED}.95.156
  • {BLOCKED}.{BLOCKED}.95.158
  • {BLOCKED}.{BLOCKED}.95.160
  • {BLOCKED}.{BLOCKED}.94.145
  • {BLOCKED}.{BLOCKED}.94.147
  • {BLOCKED}.{BLOCKED}.94.146
  • {BLOCKED}.{BLOCKED}.94.148
  • {BLOCKED}.{BLOCKED}.94.149
  • {BLOCKED}.{BLOCKED}.94.150
  • {BLOCKED}.{BLOCKED}.94.151
  • {BLOCKED}.{BLOCKED}.94.152
  • {BLOCKED}.{BLOCKED}.94.153
  • {BLOCKED}.{BLOCKED}.94.154

However, these remote sites are already inaccessible as of this writing.

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

8.478.04

FIRST VSAPI PATTERN DATE:

07 Oct 2011

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 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
    • 54dfsger = "%User Temp%\xvassdf.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • king_jp = "%System%\jpking.exe"

Step 4

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 5

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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

  • In HKEY_CLASSES_ROOT\CLSID
    • MADOWN

Step 6

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

[ Learn More ]
[AutoRun]
open=puia6h.exe
shell\open\Command=puia6h.exe

Step 7

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