BKDR_POISON.AE

 Analysis by: Michael Cabel
 Modified by: Cris Nowell Pantanilla

 ALIASES:

Backdoor.Win32.Inject.xjq (Kaspersky); 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 on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites. It may be dropped by other malware.

It does not have any propagation routine.

It connects to a website to send and receive information. However, as of this writing, the said sites are inaccessible.

It does not have any downloading capability.

It does not have any information-stealing capability.

  TECHNICAL DETAILS

File Size:

49,152 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

04 Feb 2009

Payload:

Connects to URLs/IPs

Arrival Details

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

It may be dropped by the following malware:

  • TROJ_DRPR.AS

Installation

This backdoor adds the following folders:

  • %System Root%\dfed

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

It drops the following files:

  • %System Root%\asf - empty file

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

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

  • DK#FKAIRD

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{6068A328-3774-1EEB-471C-E9AB2A6941DA}
StubPath = "{malware path and filename}"

Propagation

This backdoor does not have any propagation routine.

Backdoor Routine

This backdoor connects to the following websites to send and receive information:

  • {BLOCKED}.dyndns-free.com

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

Download Routine

This backdoor does not have any downloading capability.

Information Theft

This backdoor does not have any information-stealing capability.

NOTES:

This backdoor queries the default web browser by accessing the following registry entry:

HKEY_CLASSES_ROOT\http\shell\open\command

This backdoor does not have rootkit capabilities.

This backdoor does not exploit any vulnerability.

This malware does not communicate through proxy server.

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

5.816.02

FIRST VSAPI PATTERN DATE:

04 Feb 2009

VSAPI OPR PATTERN File:

5.817.00

VSAPI OPR PATTERN Date:

05 Feb 2009

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

Remove the malware/grayware file that dropped/downloaded BKDR_POISON.AE

Step 3

Restart in Safe Mode

[ Learn More ]

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components
    • {6068A328-3774-1EEB-471C-E9AB2A6941DA}

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.
  • %System Root%\dfed

Step 6

Search and delete this file

[ 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%\asf

Step 7

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