BKDR_DLOADER.KDS

October 09, 2012
 Analysis by: Christopher Daniel So
 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

This backdoor may be dropped by other malware.

It does not have any propagation routine.

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

It does not have any downloading capability.

It does not have any information-stealing capability.

  TECHNICAL DETAILS

File Size:

20,988,416 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

01 Jun 2012

Arrival Details

This backdoor may be dropped by the following malware:

  • TROJ_DROPPR.KDS

Propagation

This backdoor does not have any propagation routine.

Backdoor Routine

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

  • Download a file
  • Execute downloaded file
  • Get URL to download
  • Sleep for 5 seconds
  • Start a remote command prompt
  • Delete itself, remove HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run taskday, and exit

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

  • http://nec.{BLOCKED}4.com/a.php?id={random characters}
  • http://nec.{BLOCKED}4.com/b.php?id={random characters}
  • http://nec.{BLOCKED}4.com/c.php?id={random characters}
  • http://nec.{BLOCKED}4.com/d.php?id={random characters}
  • http://nec.{BLOCKED}4.com/e.php?id={random characters}
  • http://nec.{BLOCKED}4.com/f.php?id={random characters}
  • http://{BLOCKED}.{BLOCKED}.202.197/a.php?id={random characters}
  • http://{BLOCKED}.{BLOCKED}.202.197/b.php?id={random characters}
  • http://{BLOCKED}.{BLOCKED}.202.197/c.php?id={random characters}
  • http://{BLOCKED}.{BLOCKED}.202.197/d.php?id={random characters}
  • http://{BLOCKED}.{BLOCKED}.202.197/e.php?id={random characters}
  • http://{BLOCKED}.{BLOCKED}.202.197/f.php?id={random characters}

Download Routine

This backdoor does not have any downloading capability.

Information Theft

This backdoor does not have any information-stealing capability.

NOTES:

This backdoor connects to the following URL(s) to check for an Internet connection:

  • http://{BLOCKED}srv.trueidc.com/jp/0323/index.asp

It saves the command it receives as %User Temp%\temp.ini.

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.. %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp or C:\WINNT\Temp.)

It does not have rootkit capabilities.

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

9.168.03

FIRST VSAPI PATTERN DATE:

04 Jun 2012

VSAPI OPR PATTERN File:

9.169.00

VSAPI OPR PATTERN Date:

04 Jun 2012

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 the malware/grayware file that dropped/downloaded BKDR_DLOADER.KDS

Step 3

Identify and terminate files detected as BKDR_DLOADER.KDS

[ Learn More ]
  1. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  2. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 4

Search and delete this file

[ 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.
  • %User Temp%\temp.ini

Step 5

Scan your computer with your Trend Micro product to delete files detected as BKDR_DLOADER.KDS. 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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