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TROJ_GAMETHIE.OH

October 12, 2012
 ALIASES:

Worm:Win32/Emerleox.gen!A (Microsoft); W32/Fujacks.az (McAfee); Suspicious.DLoader (Symantec); Worm.Win32.Fujack.ci (Kaspersky); Worm.Win32.Emerleox.gen.a (v) (Sunbelt); Trojan.Packed.12223 (FSecure)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW


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

It modifies files, disabling programs and applications from properly running.

  TECHNICAL DETAILS

File Size:

311,479 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

06 Mar 2012

Arrival Details

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

  • %System%\drivers\suchost.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.)

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Explorer = "%System%\drivers\suchost.exe"

Other System Modifications

This Trojan modifies the following files:

  • %Windows%\Tasks\SA.DAT

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

It deletes the following folders:

  • %System Root%\autorun.inf

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

It adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
AVP.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
RavMon.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
RavMonD.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
RavStub.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
RavTask.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
CCenter.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
360tray.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
360Safe.exe

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
AVP.exe
Debugger = "ntsd -d"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
RavMon.exe
Debugger = "ntsd -d"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
RavMonD.exe
Debugger = "ntsd -d"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
RavStub.exe
Debugger = "ntsd -d"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
RavTask.exe
Debugger = "ntsd -d"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
CCenter.exe
Debugger = "ntsd -d"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
360tray.exe
Debugger = "ntsd -d"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
360Safe.exe
Debugger = "ntsd -d"

It modifies the following registry entries:

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.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoDriveTypeAutoRun = "8"

(Note: The default value data of the said registry entry is 91.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Prefetcher
Version = "11"

(Note: The default value data of the said registry entry is 11.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Prefetcher
StartTime = "2012/02/27-16:12:15"

(Note: The default value data of the said registry entry is 2011/12/21-02:22:02.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Prefetcher
TracesProcessed = "0"

(Note: The default value data of the said registry entry is 9.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Prefetcher
TracesSuccessful = "0"

(Note: The default value data of the said registry entry is 6.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Prefetcher
LastTraceFailure = "0"

(Note: The default value data of the said registry entry is 4.)

Dropping Routine

This Trojan drops the following files:

  • %System Root%\go.sys
  • %Program Files%\Desktop_.ini
  • %Program Files%\MSN Gaming Zone\Desktop_.ini
  • %Program Files%\Online Services\Desktop_.ini
  • %Program Files%\Uninstall Information\Desktop_.ini
  • %Program Files%\WinPcap\Desktop_.ini
  • %Program Files%\xerox\Desktop_.ini
  • %Program Files%\xerox\nwwia\Desktop_.ini
  • %System Root%\RECYCLER\Desktop_.ini
  • %System Root%\RECYCLER\S-1-5-21-436374069-362288127-839522115-1003\Desktop_.ini
  • %System Root%\RECYCLER\S-1-5-21-436374069-362288127-839522115-500\Desktop_.ini
  • %System Root%\autorun.inf
  • %User Temp%\myUPdatetxt.txt
  • %System Root%\¡¡¡¡¡¡.exe

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %Program Files% is the default Program Files folder, usually C:\Program Files.. %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.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://www.{BLOCKED}g08.com/down/down.txt

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.200

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 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\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options
    • AVP.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options
    • RavMon.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options
    • RavMonD.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options
    • RavStub.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options
    • RavTask.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options
    • CCenter.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options
    • 360tray.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options
    • 360Safe.exe

Step 4

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
    • Explorer = "%System%\drivers\suchost.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\AVP.exe
    • Debugger = "ntsd -d"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\RavMon.exe
    • Debugger = "ntsd -d"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\RavMonD.exe
    • Debugger = "ntsd -d"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\RavStub.exe
    • Debugger = "ntsd -d"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\RavTask.exe
    • Debugger = "ntsd -d"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\CCenter.exe
    • Debugger = "ntsd -d"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\360tray.exe
    • Debugger = "ntsd -d"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\360Safe.exe
    • Debugger = "ntsd -d"

Step 5

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\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
    • From: CheckedValue = "0"
      To: CheckedValue = ""1""
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
    • From: NoDriveTypeAutoRun = "8"
      To: NoDriveTypeAutoRun = ""91""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Prefetcher
    • From: Version = "11"
      To: Version = ""11""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Prefetcher
    • From: StartTime = "2012/02/27-16:12:15"
      To: StartTime = ""2011/12/21-02:22:02""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Prefetcher
    • From: TracesProcessed = "0"
      To: TracesProcessed = ""9""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Prefetcher
    • From: TracesSuccessful = "0"
      To: TracesSuccessful = ""6""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Prefetcher
    • From: LastTraceFailure = "0"
      To: LastTraceFailure = ""4""

Step 6

Search and delete these files

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %System Root%\go.sys
  • %Program Files%\Desktop_.ini
  • %Program Files%\MSN Gaming Zone\Desktop_.ini
  • %Program Files%\Online Services\Desktop_.ini
  • %Program Files%\Uninstall Information\Desktop_.ini
  • %Program Files%\WinPcap\Desktop_.ini
  • %Program Files%\xerox\Desktop_.ini
  • %Program Files%\xerox\nwwia\Desktop_.ini
  • %System Root%\RECYCLER\Desktop_.ini
  • %System Root%\RECYCLER\S-1-5-21-436374069-362288127-839522115-1003\Desktop_.ini
  • %System Root%\RECYCLER\S-1-5-21-436374069-362288127-839522115-500\Desktop_.ini
  • %System Root%\autorun.inf
  • %User Temp%\myUPdatetxt.txt
  • %System Root%\¡¡¡¡¡¡.exe

Step 7

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

Step 8

Restore deleted/modified files and/or registry entries from backup

*Note: Only Microsoft-related files/keys/values will be restored. If this malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

    • %Windows%\Tasks\SA.DAT


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