ALIASES:

VirTool:Win32/VBInject (Microsoft); Generic.dx!b2w4 (McAfee); Trojan.Gen (Symantec); ARC:Rsrc-Package, ARC:[data0000.cab]:CAB, [data0000.cab/Crypted2.exe]:Trojan.Win32.Buzus.iiln (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan.Generic.6488945 (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.

  TECHNICAL DETAILS

File Size: 680,960 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 28 Nov 2011

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 creates the following folders:

  • %User Temp%\IXP000.TMP

(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.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunOnce
wextract_cleanup0 = "rundll32.exe %System%\advpack.dll,DelNodeRunDLL32 "%User Temp%\IXP000.TMP\""

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{8BF1D336-BE58-5C59-1D0A-84694448C393}
StubPath = "%User Temp%\IXP000.TMP\Crypted2.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
azws = "%User Temp%\IXP000.TMP\Crypted2.exe"

Other System Modifications

This Trojan deletes the following folders:

  • %User Temp%\IXP000.TMP\

(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 adds the following registry keys:

HKEY_CURRENT_USER\Software\Enigma Protector\
8941475D2CB361B8-F3AC09F103794CBA\7726CF4135C94ECC-768EAD6D4874B8DF

HKEY_LOCAL_MACHINE\Software\Microsoft\
Active Setup\Installed Components\{8BF1D336-BE58-5C59-1D0A-84694448C393}

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Enigma Protector\
8941475D2CB361B8-F3AC09F103794CBA\7726CF4135C94ECC-768EAD6D4874B8DF
B3FFB43E = {random values}

It deletes the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Active Setup\Installed Components\{8BF1D336-BE58-5C59-1D0A-84694448C393}

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\IXP000.TMP\TMP4351$.TMP
  • %User Temp%\IXP000.TMP\Crypted2.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.)

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_CURRENT_USER\Software\Enigma Protector\8941475D2CB361B8-F3AC09F103794CBA
    • 7726CF4135C94ECC-768EAD6D4874B8DF
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Active Setup\Installed Components
    • {8BF1D336-BE58-5C59-1D0A-84694448C393}

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce
    • wextract_cleanup0="rundll32.exe %System%\advpack.dll,DelNodeRunDLL32 "%User Temp%\IXP000.TMP\""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{8BF1D336-BE58-5C59-1D0A-84694448C393}
    • StubPath="%User Temp%\IXP000.TMP\Crypted2.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • azws="%User Temp%\IXP000.TMP\Crypted2.exe"
  • In HKEY_CURRENT_USER\Software\Enigma Protector\8941475D2CB361B8-F3AC09F103794CBA\7726CF4135C94ECC-768EAD6D4874B8DF
    • B3FFB43E={random values}

Step 5

Search and delete this folder

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result. %User Temp%\IXP000.TMP

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.
  • %User Temp%\IXP000.TMP\TMP4351$.TMP
  • %User Temp%\IXP000.TMP\Crypted2.exe

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_AGENT_002949.TOMB. 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 these deleted registry keys/values from backup

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

  • In HKEY_CURRENT_USER\Software\Microsoft\Active Setup\Installed Components
    • {8BF1D336-BE58-5C59-1D0A-84694448C393}


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