Analysis by: Abraham Latimer Camba
 Modified by: Michael Cabel
ALIASES:

Backdoor.Darkmoon (Symantec), BackDoor-AMQ.dr (McAfee)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware, Downloaded from the Internet

This backdoor arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It does not have any propagation routine.

However, as of this writing, the said sites are inaccessible.

It does not drop any other file.

  TECHNICAL DETAILS

Ports: Port 80
File Size: 45,056 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 05 Apr 2012
Payload: Compromises system security, Connects to URLs/IPs

Arrival Details

This backdoor arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

It 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 backdoor adds the following mutexes to ensure that only one of its copies runs at any one time:

  • 2ddwd2d

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
office update = "{malware path and file name}"

Other System Modifications

This backdoor adds the following registry keys:

HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications

Propagation

This backdoor does not have any propagation routine.

Backdoor Routine

This backdoor opens the following port(s) where it listens for remote commands:

  • TCP port 80

It connects to the following URL(s) to send and receive commands from a remote malicious user:

  • {BLOCKED}11.9966.org

However, as of this writing, the said sites are inaccessible.

Dropping Routine

This backdoor does not drop any other file.

NOTES:

This backdoor have the following capabilities over the compromised system:

  • Capture screen, audio, and webcam
  • Execute binary instructions
  • Key logger
  • List active ports
  • Manage open Windows
  • Manage passwords
  • Manage registry, processes, services, devices, and installed applications
  • Perform multiple simultaneous transfers
  • Perform remote shell
  • Relay server
  • Searh files
  • Share servers
  • Update, restart, terminates itself

This backdoor does not have rootkit capabilities.

This backdoor does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.888.05
FIRST VSAPI PATTERN DATE: 05 Apr 2012
VSAPI OPR PATTERN File: 8.889.00
VSAPI OPR PATTERN Date: 06 Apr 2012

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

Identify and terminate files detected as BKDR_POISON.BJX

[ Learn More ]
  1. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  2. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • office update = "{malware path and file name}"

Step 4

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
    • Local AppWizard-Generated Applications

Step 5

Scan your computer with your Trend Micro product to delete files detected as BKDR_POISON.BJX. 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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