BKDR_DESTOVER.A

December 04, 2014
 Analysis by: Anthony Joe Melgarejo
 ALIASES:

Backdoor.Destover (Symantec)

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware

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

  TECHNICAL DETAILS

File Size:

86,016 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

03 Dec 2014

Payload:

Collects system information

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.

Autostart Technique

This backdoor drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:

  • %User Startup%\{malware file name}.exe

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.)

Backdoor Routine

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

  • Move specified file to another directory
  • Enumerate files in specified directory
  • Enumerate fixed drives and retrieve free disk space
  • Download arbitrary files
  • Upload arbitrary files
  • Execute arbitrary files
  • Drop a dummy file
  • Check for a specified file's existence
  • Enumerate Processes and Modules
  • Terminate specified process
  • Gather system information
  • Reconfigure CnC connection
  • Retrieve current working directory and change to another

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

  • {BLOCKED}3.{BLOCKED}1.222.102:443
  • {BLOCKED}8.{BLOCKED}5.226.235:443

NOTES:

It gathers the following information:

  • Computer name
  • Operating system version
  • Processor information
  • IPv4 connections
  • Existence of a specified process
  • Data from specified registry entry
  • Network Adapter information

  SOLUTION

Minimum Scan Engine:

9.700

FIRST VSAPI PATTERN FILE:

11.316.04

FIRST VSAPI PATTERN DATE:

03 Dec 2014

VSAPI OPR PATTERN File:

11.317.00

VSAPI OPR PATTERN Date:

04 Dec 2014

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Scan your computer with your Trend Micro product to delete files detected as BKDR_DESTOVER.A. 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.


Did this description help? Tell us how we did.