TROJ_GAMETHI.GEQ
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Trojan may be downloaded by other malware/grayware/spyware from remote sites. It may be unknowingly downloaded by a user while visiting malicious websites.
It is injected into all running processes to remain memory resident.
TECHNICAL DETAILS
114,688 bytes
EXE
Yes
23 Aug 2011
Arrival Details
This Trojan may be downloaded by other malware/grayware/spyware from remote sites.
It may be unknowingly downloaded by a user while visiting malicious websites.
Installation
This Trojan drops the following copies of itself into the affected system:
- %System%\ahnsbsb.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.)
It drops the following files:
- %System%\ahnfgss0.dll
- %System%\ahnxsds0.dll
(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.)
It is injected into all running processes to remain memory resident.
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CLASSES_ROOT\CLSID\{AF4DA69B-E1D6-469A-855B-6445294857D4}\
InprocServer32
Default = "%System%\ahnxsds0.dll"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
ahnsoft = "%System%\ahnsbsb.exe"
Other System Modifications
This Trojan 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.)
SOLUTION
8.900
7.590.05
03 Nov 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_CLASSES_ROOT\CLSID\{AF4DA69B-E1D6-469A-855B-6445294857D4}\InprocServer32
- Default = "%System%\ahnxsds0.dll"
- Default = "%System%\ahnxsds0.dll"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- ahnsoft = "%System%\ahnsbsb.exe"
- ahnsoft = "%System%\ahnsbsb.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: Hidden = "1"
- From: Hidden = "2"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: ShowSuperHidden = "0"
To: ShowSuperHidden = "1"
- From: ShowSuperHidden = "0"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
- From: CheckedValue = "0"
To: CheckedValue = "1"
- From: CheckedValue = "0"
Step 5
Search and delete these files
- %System%\ahnfgss0.dll
- %System%\ahnxsds0.dll
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_GAMETHI.GEQ. 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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