TROJ_PAM_00000205BE.T3

October 13, 2012
 ALIASES:

Backdoor:Win32/Zegost.AF (Microsoft); Generic Backdoor.to (McAfee); Trojan.Gen (Symantec); BehavesLike.Win32.Malware.dlw (mx-v) (Sunbelt); Backdoor:W32/Hupigon.OMO (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:

143,631 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

21 Jul 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:

  • %Windows%\svchcst.exe

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

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\NetSubKey

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\MediaResources\msvideo

HKEY_CURRENT_USER\Software\Microsoft\
Windows Script\Settings

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows Script\Settings
JITDebug = "0"

Dropping Routine

This Trojan drops the following files:

  • %System Root%\5568D629.vbs
  • %System Root%\B005CB47.vbs
  • %System Root%\9E48EA9A.vbs
  • %System Root%\C9F2281E.vbs
  • %System Root%\28DB993C.vbs
  • %System Root%\94C7ADD7.vbs
  • %System Root%\D3A80CF1.vbs
  • %System Root%\23B48273.vbs
  • %System Root%\F2AD2640.vbs
  • %System Root%\3D48F37C.vbs
  • %System Root%\4D4C686C.vbs
  • %System Root%\B861B669.vbs
  • %Windows%\svchcst.exe

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

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://jckins.{BLOCKED}2.org/mao/jkc.exe

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

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
    • NetSubKey
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\MediaResources
    • msvideo
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows Script
    • Settings

Step 3

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 Script\Settings
    • JITDebug = "0"

Step 4

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%\5568D629.vbs
  • %System Root%\B005CB47.vbs
  • %System Root%\9E48EA9A.vbs
  • %System Root%\C9F2281E.vbs
  • %System Root%\28DB993C.vbs
  • %System Root%\94C7ADD7.vbs
  • %System Root%\D3A80CF1.vbs
  • %System Root%\23B48273.vbs
  • %System Root%\F2AD2640.vbs
  • %System Root%\3D48F37C.vbs
  • %System Root%\4D4C686C.vbs
  • %System Root%\B861B669.vbs
  • %Windows%\svchcst.exe

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_PAM_00000205BE.T3. 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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