Analysis by: Michael Cabel
 Modified 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

This backdoor may be dropped by other malware.

It executes commands from a remote malicious user, effectively compromising the affected system.

  TECHNICAL DETAILS

File Size: 29,184 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 19 Sep 2012
Payload: Compromises system security, Collects system information, Executes files

Arrival Details

This backdoor may be dropped by the following malware:

Backdoor Routine

This backdoor executes the following commands from a remote malicious user:

  • Execute files
  • Perform remote shell
  • Sleep for a specified amount of time
  • Download file from C&C server

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

  • https://{BLOCKED}3.{BLOCKED}4.207.193/CEL{random number}={random number}.cgi?{random characters}
  • https://{BLOCKED}3.{BLOCKED}4.207.193/DES{random number}={random number}.cgi?{random characters}
  • https://{BLOCKED}3.{BLOCKED}4.207.193/RES{random number}={random number}.cgi?{random characters}
  • https://{BLOCKED}3.{BLOCKED}4.207.193/SDU{random number}={random number}.cgi?{random characters}

It posts the following information to its command and control (C&C) server:

  • Computer name
  • Local IP address
  • Malware ID
  • OS version
  • Proxy server IP and port
  • User name

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 9.406.03
FIRST VSAPI PATTERN DATE: 19 Sep 2012
VSAPI OPR PATTERN File: 9.407.00
VSAPI OPR PATTERN Date: 19 Sep 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

Remove the malware/grayware file that dropped/downloaded BKDR_DEMTRAN.RE

Step 3

Identify and terminate files detected as BKDR_DEMTRAN.RE

[ 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 4

Scan your computer with your Trend Micro product to delete files detected as BKDR_DEMTRAN.RE. 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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