Analysis by: Erika Bianca Mendoza


Windows 2000, XP, Server 2003


  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes


This Trojan may be downloaded by other malware/grayware from remote sites.

As of this writing, the said sites are inaccessible.

It steals sensitive information such as user names and passwords related to certain games.

It creates an event. It deletes itself after execution.


File Size: 102,587 bytes
File Type: PE
Memory Resident: Yes
Initial Samples Received Date: 28 Aug 2008
Payload: Terminates processes

Arrival Details

This Trojan may be downloaded by the following malware/grayware from remote sites:



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

  • %system%{5 random characters}.exe

It injects itself into the following processes as part of its memory residency routine:


Autostart Technique

This Trojan modifies the following entry(ies) to allow itself to run on safe mode:

Windows NT\CurrentVersion\Winlogon
Userinit = %system%\userinit.exe,aoots.exe

(Note: The default value data of the said registry entry is %system%\userinit.exe,.)

Process Termination

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

  • AYUpdate.aye
  • SfFnUp.exe
  • UfUpdUi.exe
  • avast.setup
  • avgupd.exe
  • luall.exe
  • mcupdate.exe
  • preupd.exe
  • setup.ovr
  • update.exe

Download Routine

This Trojan connects to the following URL(s) to download its component file(s):

  • www.{BLOCKED}
  • 23weer.7{BLOCKED}.com/23weer/23weer.gif

As of this writing, the said sites are inaccessible.

Information Theft

This Trojan steals sensitive information such as user names and passwords related to the following games:

  • Maple Story
  • Dungeon Fighter
  • Ragnarok Online
  • World of Warcraft
  • Twelve Sky 2
  • Red Stone
  • Tales Weaver
  • FIFA

Other Details

This Trojan does the following:

  • Checks the language by querying on the following registry:
    If Chinese, it does not continue with its routines.
  • Obtains user account details from the above-mentioned games by monitoring the following processes:
    • maplestory.exe
    • arad.exe
    • ragexe.exe
    • ragurdrexe.exe
    • wow.exe
    • gersang.exe
    • twelvesky2.exe
    • RedStone.exe
    • InphaseNXD.exe
    • dnf.exe
    • ff2client.exe
    • _beanfuncore.exe
    • elementclient.exe
    • ragfree.exe
    • pcotp.exe

It creates the following event(s):


It deletes itself after execution.


Minimum Scan Engine: 8.900
VSAPI OPR PATTERN File: 7.351.00
VSAPI OPR PATTERN Date: 31 Jul 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

Restart in Safe Mode

[ Learn More ]

Step 3

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
    • From: Userinit = %system%\userinit.exe,aoots.exe
      To: Userinit = %system%\userinit.exe

Step 4

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