WORM_GAMETHI.GRZ
Windows 2000, XP, Server 2003

Threat Type: Worm
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
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 executes then deletes itself afterward.
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 steals sensitive information such as user names and passwords related to certain games.
It opens a hidden Internet Explorer window.
TECHNICAL DETAILS
Varies
PE
Yes
02 Jul 2010
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 copies of itself into the affected system:
- %User Temp%\xvassdf.exe
(Note: %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 file(s)/component(s):
- %User Temp%\4tddfwq0.dll - also detected as WORM_GAMETHI.GRZ
(Note: %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.)
Its DLL component is injected to the following process(es):
- {All Running Processes}
It executes then deletes itself afterward.
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
54dfsger = %User Temp%\xvassdf.exe
Other System Modifications
This worm 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
- CCSVCHST.EXE
- EKRN.EXE
- InphaseNXD.EXE
- LIVESRV.EXE
- SfFnUp.exe
- UFSEAGNT.EXE
- UfUpdUi.exe
- Update.exe
- VCRMON.EXE
- VSTSKMGR.EXE
- avgupd.exe
- luall.exe
- mcupdate.exe
- preupd.exe
- update.exe
Download Routine
This worm downloads updated copies of itself from the following websites:
- http://www.{BLOCKED}d3.com/1rb/ar1.rar
- http://www.{BLOCKED}lk.com/1rb/ar.rar
Information Theft
This worm steals sensitive information such as user names and passwords related to the following games:
- ARAD.exe
- Atlantica.exe
- Ragexe.exe
- coc.exe
- red stone.exe
- maplestory.exe
- pol.exe
- cabalmain.exe
- InphaseNXD.EXE
Other Details
This worm opens a hidden Internet Explorer window.
It does the following:
- Attempts to steal information from the file AAA.DAT
- Attempts to capture Yahoo! account login credentials whenever the following URLs are accessed:
- https://login.yahoo.co.jp/config/login_verify2?.src=ym
- https://login.yahoo.co.jp/config/login?
- Monitors traffic going to the following IP addresses:
- 59.128.94.145
- 59.128.94.146
- 59.128.94.147
- 59.128.94.148
- 59.128.94.149
- 59.128.94.150
- 59.128.94.151
- 59.128.94.152
- 59.128.94.153
- 59.128.94.154
- 59.128.95.128
- 59.128.95.130
- 59.128.95.132
- 59.128.95.134
- 59.128.95.136
- 59.128.95.138
- 59.128.95.140
- 59.128.95.142
- 59.128.95.144
- 59.128.95.146
- 59.128.95.148
- 59.128.95.150
- 59.128.95.152
- 59.128.95.154
- 59.128.95.156
- 59.128.95.158
- 59.128.95.160
SOLUTION
8.900
7.454.02
10 Sep 2010
7.455.00
10 Sep 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
Step 3
Delete this registry value
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
- 54dfsger = %User Temp%\xvassdf.exe
Step 4
Restore this modified registry value
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: 1
- From: Hidden = 2
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: ShowSuperHidden = 0
To: 1
- From: ShowSuperHidden = 0
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
- From: CheckedValue = 0
To: 1
- From: CheckedValue = 0
Step 5
Search and delete AUTORUN.INF files created by WORM_GAMETHI.GRZ that contain these strings
open=puia6h.exe
shell\open\Command=puia6h.exe
Step 6
Scan your computer with your Trend Micro product to delete files detected as WORM_GAMETHI.GRZ. 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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