Analysis by: Mark Joseph Manahan
ALIASES:

Backdoor:Win32/Turkojan.AI (Microsoft), probably a variant of Win32/Agent.JEUZHOC trojan (Eset), W32/Boltolog.ASK!tr.dldr (Fortinet), Trojan-Downloader.Win32.Boltolog (Ikarus)

 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 executes commands from a remote malicious user, effectively compromising the affected system. It connects to a website to send and receive information.

It also has rootkit capabilities, which enables it to hide its processes and files from the user.

  TECHNICAL DETAILS

File Size: 1,539,989 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 14 Nov 2012
Payload: Compromises system security, Hides files and processes, Drops 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.

Installation

This backdoor drops and executes the following files:

  • %Windows%\cmsetac.dll - detected as BKDR_TURKO.SMD
  • %Windows%\mstwain32.exe - also detected as BKDR_TURKOJAN.A
  • %Windows%\ntdtcstp.dll - also detected as BKDR_TURKOJAN.A

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

Autostart Technique

This backdoor adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
mstwain32 = "%Windows%\mstwain32.exe"

Backdoor Routine

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

  • Get Saved Passwords
  • Remote Access
  • View webcam stream
  • Record audio stream
  • Manage clipboard (Read, Set, Clear, Lock, Unlock)
  • Manage browser (Visit, Set homepage, View last visited)
  • Show Running Applications
  • Manage Applications (Maximize, Minimize, Close, Show, Hide, Activate, Deactivate,Hide Close Button, Change Title, Flash)
  • Manage Service (List, Start, Stop, Uninstall)
  • Manage registries (List, Add, Modify, Delete)
  • Manage mouse activity (Control, Crazy, Bungi, Set speed, Set mouse trail, Set double click speed, Lock, Unlocked)
  • Change resolution
  • Manage Keyboard (Lock Keys, Set Keyboard lights)
  • Capture keystrokes
  • Chat with victim
  • Display Message Box
  • Capture msn logs
  • Manage Files and Directory (Add, Delete, Download, Upload, Execute, Compress, Search)
  • Remote shell command
  • Block/Unblock websites
  • Update self
  • View System Informations
  • View Installed Applications
  • Manage Desktop (Show/Hide/Lock/Unlock Desktop, Show/Hide/Lock/Unlock Start/Button,Show/Hide Task Icons, Show/Hide System Clock, On/Off Monitor, Open/Close CD-Rom, Show/Hide/Lock/Unlock Taskbar)
  • Flip screen vertical/horizontal
  • Shutdown, reboot, log off

It connects to the following websites to send and receive information:

  • {BLOCKED}nhaconta.no-ip.biz:15963

Rootkit Capabilities

This backdoor also has rootkit capabilities, which enables it to hide its processes and files from the user.

Dropping Routine

This backdoor drops the following file(s), which it uses for its keylogging routine:

  • %Windows%\KB8888239.log

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 9.526.02
FIRST VSAPI PATTERN DATE: 14 Nov 2012
VSAPI OPR PATTERN File: 9.527.00

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 malware files dropped/downloaded by BKDR_TURKOJAN.A

     BKDR_TURKO.SMD

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

 
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • mstwain32 = "%Windows%\mstwain32.exe"

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.
  • %Windows%\KB8888239.log

Step 6

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


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