TSPY_GAMETHI.ZZ

October 16, 2012
 Analysis by: Marfel Tiamzon
 PLATFORM:

Windows 98, ME, NT, 2000, XP, Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This spyware arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size:

78,592 bytes

File Type:

EXE

Memory Resident:

Yes

Arrival Details

This spyware arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This spyware drops the following component file(s):

  • %system%\netsvcs_v0x0li.dLl - detected as TSPY_GAMETHI.ZZ
  • %Program Files%\Internet Explorer\sxs.dll - detected as TSPY_GAMETHI.ZZ

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)

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

  • SVCHOST.EXE
  • CSRSS.EXE
  • WINLOGON.EXE
  • Explorer.exe

Autostart Technique

This spyware registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\netsvcs_v0x0
ImagePath = %System Root%\System32\svchost.exe -k netsvcs

Other System Modifications

This spyware modifies the following registry key(s)/entry(ies) as part of its installation routine:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\ServiceCurrent
@ = b

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\SvcHost
netsvcs = {hex value}

(Note: The default value data of the said registry entry is {hex value}.)

  SOLUTION

Minimum Scan Engine:

8.900

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

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\SYSTEM\CurrentControlSet\Services\
    • netsvcs_v0x0

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\SYSTEM\CurrentControlSet\Control\ServiceCurrent
    • From: @ = b
      To: @ = a
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SvcHost
    • From: netsvcs = {hex value}
      To: netsvcs = {default hex value}

Step 4

Scan your computer with your Trend Micro product to delete files detected as TSPY_GAMETHI.ZZ. 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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