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BKDR_TURKOJAN.CU

October 06, 2013
 Modified by: Mark Joseph Manahan
 ALIASES:

Backdoor:Win32/Turkojan.A (Microsoft); BackDoor-CZP.dr.gen.a (McAfee); Backdoor.Turkojan (Symantec); Trojan-Dropper.Win32.Typic.cak (Kaspersky); Backdoor.Win32.Turkojan.il (v) (Sunbelt); Backdoor:W32/Turkojan.gen!A (FSecure)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 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.

It connects to a website to send and receive information.

  TECHNICAL DETAILS

File Size:

276,992 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

05 Jan 2010

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 the following copies of itself into the affected system:

  • %Windows%\microsoft.exe

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

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
microsoft = "%Windows%\microsoft.exe"

Backdoor Routine

This backdoor connects to the following websites to send and receive information:

  • {BLOCKED}n-hi.no-ip.org:15963

Dropping Routine

This backdoor drops the following files:

  • %Windows%\KB8888239.log
  • %Windows%\ntdtcstp.dll
  • %Windows%\cmsetac.dll

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

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

6.746.02

FIRST VSAPI PATTERN DATE:

05 Jan 2010

VSAPI OPR PATTERN File:

6.747.00

VSAPI OPR PATTERN Date:

06 Jan 2010

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

Restart in Safe Mode

[ Learn More ]

Step 3

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
    • microsoft = "%Windows%\microsoft.exe"

Step 4

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.
  • %Windows%\KB8888239.log
  • %Windows%\cmsetac.dll
  • %Windows%\ntdtcstp.dll

Step 5

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