Analysis by: Abraham Latimer Camba

 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 does not have any propagation routine.

It reads its configuration file that contains commands and data to be sent to a remote server. However, as of this writing, the said sites are inaccessible.

It does not drop any other file.

As of this writing, the said sites are inaccessible.

It does not have any information-stealing capability.

It requires its main component to successfully perform its intended routine.

  TECHNICAL DETAILS

File Size: 51,248,080 bytes
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 16 Aug 2012
Payload: Downloads files

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.

Propagation

This backdoor does not have any propagation routine.

Backdoor Routine

This backdoor reads its configuration file that contains commands and data to be sent to a remote server.

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

  • http://{BLOCKED}n.outlookrevision.com

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

Dropping Routine

This backdoor does not drop any other file.

Download Routine

This backdoor connects to the following URL(s) to download its configuration file:

  • http://{BLOCKED}n.outlookrevision.com

It saves the files it downloads using the following names:

  • %User Temp%\{computer name}.ax

(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.)

As of this writing, the said sites are inaccessible.

Information Theft

This backdoor does not have any information-stealing capability.

Other Details

This backdoor requires its main component to successfully perform its intended routine.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 9.328.07
FIRST VSAPI PATTERN DATE: 16 Aug 2012
VSAPI OPR PATTERN File: 9.329.00
VSAPI OPR PATTERN Date: 17 Aug 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

Scan your computer with your Trend Micro product and note files detected as BKDR_AGENTE.BTM

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Search and delete the file detected as BKDR_AGENTE.BTM

*Note: Some component files may be 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.

To manually delete a malware/grayware file from the affected system:

  1. Right-click Start then click Search....
  2. In the Named input box, type the name of the file that was detected earlier.
  3. In the Look In drop-down list, select My Computer then press Enter.
  4. Once located, select the file then press SHIFT+DELETE to delete it.

Step 5

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%\{computer name}.ax

Step 6

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