Analysis by: rolandde

 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

This backdoor may be dropped by other malware.

It connects to a website to send and receive information.

It logs a user's keystrokes to steal information.

  TECHNICAL DETAILS

File Size: 91,136 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 02 Jan 2012

Arrival Details

This backdoor may be dropped by the following malware:

  • TROJ_MDROP.SMCM

Installation

This backdoor drops and executes the following files:

  • %System%\Msdirects.sys - detected as RTKT_SVNLOOC.A
  • %System%\KernelExec.sys - detected as RTKT_SVNLOOC.A
  • %System%\Msdirects.dll - also detected as BKDR_SVNLOOC.A

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It drops the following non-malicious file:

  • %System%\Config.ini - configuration file

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

Backdoor Routine

This backdoor opens the following port(s) where it listens for remote commands:

  • port 389

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

  • {BLOCKED}5.{BLOCKED}3.189.147

Information Theft

This backdoor logs a user's keystrokes to steal information.

Stolen Information

This backdoor saves the stolen information in the following file:

  • %System%\Syslog.sys

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

NOTES:

It injects its dropped DLL, %System%\Msdirects.sys, to running process in the memory in order to stay memory resident.

It uses the following rootkit components to achieve the above-mentioned routine and to hide its component files and registries:

  • %System%\KernelExec.sys
  • %System%\Msdirects.dll

It is capable of executing the following backdoor commands:

  • Query and view open windows
  • View, get, or query host
  • Start, stop, or change its own service
  • Enumerate or query services
  • Query or view processes
  • Uninstall itself
  • Query, view, delete, or check the size of its log file where it saves the stolen information
  • Start and stop keylogging
  • Download a file
  • Delete a file
  • Execute a file
  • Create a new folder
  • Open command shell
  • Upload a file
  • Query or browse directories
  • Query or check for existing drives
  • Set or get user identity
  • Monitor USB drives and check the existing folders in it
  • Open an FTP connection
  • Open an HTTP connection
  • Shutdown the system
  • Check operating system version
  • Get processor information and number of processors

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.686.03
FIRST VSAPI PATTERN DATE: 02 Jan 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 malware files dropped/downloaded by BKDR_SVNLOOC.A

    • RTKT_SVNLOOC.A
    • TROJ_MDROP.SMCM

Step 3

Scan your computer with your Trend Micro product and note files detected as BKDR_SVNLOOC.A

Step 4

Restart in Safe Mode

[ Learn More ]

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.  
  • %System%\Config.ini
  • %System%\Syslog.sys

Step 6

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


Did this description help? Tell us how we did.