BKDR_DARKOMET.BE

March 07, 2015
 ALIASES:

Backdoor.Win32.DarkKomet.etjg (Kaspersky)

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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.

  TECHNICAL DETAILS

File Size:

1,659,392 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

19 Feb 2015

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.

Installation

This backdoor creates the following folders:

  • %User Profile%\Application Data\FolderName

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Other System Modifications

This backdoor deletes the following files:

  • %User Profile%\Application Data\ svhost.exe
  • %User Profile%\FolderName\rundll11-.txt
  • %User Profile%\FolderName\file.exe:Zone.Identifier
  • %User Startup%\file.exe:Zone.Identifier

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %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.)

Dropping Routine

This backdoor drops the following files:

  • %User Profile%\FolderName\mata2.bat
  • %User Profile%\FolderName\invs.vbs
  • %User Profile%\FolderName\mata.bat
  • %User Profile%\FolderName\svhost.bat

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.700

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

Search and delete these components

[ Learn More ]
There may be some components 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 Profile%\FolderName\mata2.bat
  • %User Profile%\FolderName\invs.vbs
  • %User Profile%\FolderName\mata.bat
  • %User Profile%\FolderName\svhost.bat

Step 3

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.
  • %User Profile%\Application Data\FolderName

Step 4

Scan your computer with your Trend Micro product to delete files detected as BKDR_DARKOMET.BE. 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.

Step 5

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %User Profile%\Application Data\ svhost.exe
  • %User Profile%\FolderName\rundll11-.txt
  • %User Profile%\FolderName\file.exe:Zone.Identifier
  • %User Startup%\file.exe:Zone.Identifier


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