Analysis by: Jaime Benigno Reyes
ALIASES:

Backdoor.Win32.MiniDuke.e (Kaspersky), Packed.Win32.Krap (Ikarus)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

 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.

  TECHNICAL DETAILS

File Size: 22,528 bytes
File Type: DLL, PE
Memory Resident: Yes
Initial Samples Received Date: 28 Feb 2013
Payload: Connects to URLs/IPs, Compromises system security, Downloads files

Arrival Details

This backdoor may be dropped by the following malware:

Installation

This backdoor drops the following copies of itself into the affected system and executes them:

  • All Users' %User Profile%\{random name}.{random extension}

(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.)

Autostart Technique

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

  • All Users' %User Startup%\{random name}.lnk

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

  • {BLOCKED}ks.ch
  • {BLOCKED}s.org
  • {BLOCKED}nline.com
  • www.{BLOCKED}m.com
  • www.{BLOCKED}0.com

NOTES:

The C&C server it connects to depends on information obtained from specific Twitter accounts or on information obtained using Google search.

It downloads file from its C&C server and executes it. The file it downloads depends on the C& C server as well as the infected system.

The downloaded file may have the following capabilities:

  • Copy/move files
  • Create directories
  • Delete files
  • Download and execute files
  • Terminate process

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 9.758.04
FIRST VSAPI PATTERN DATE: 28 Feb 2013
VSAPI OPR PATTERN File: 9.759.00
VSAPI OPR PATTERN Date: 01 Mar 2013

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

Remove the malware/grayware file that dropped/downloaded BKDR_MINIDUKE.SM

Step 3

Scan your computer with your Trend Micro product and note files detected as BKDR_MINIDUKE.SM

Step 4

Restart in Safe Mode

[ Learn More ]

Step 5

Search and delete files detected as BKDR_MINIDUKE.SM

[ 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.

Step 6

Search and delete these files

[ Learn More ]
There may be some 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.
  • All Users' %User Startup%\{random name}.lnk

Step 7

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