Analysis by: JasperM
 PLATFORM:

Windows 2000, XP, Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This backdoor is a command line tool called HUC Packet and Socks5 Transmit Tool.

This backdoor may be dropped by other malware. It may be unknowingly downloaded by a user while visiting malicious websites.

It acts as a proxy server to allow remote malicious user to use the affected systems to hide their identities when performing malicious activities.

  TECHNICAL DETAILS

Ports: User-specified
File Size: 90,112 bytes
File Type: PE
Memory Resident: Yes
Initial Samples Received Date: 16 Sep 2010

Arrival Details

This backdoor may be dropped by other malware.

It may be unknowingly downloaded by a user while visiting malicious websites.

Autostart Technique

This backdoor registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\HTran
ImagePath = "{malware path and file name}.EXE -run"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\HTran
DisplayName = "Proxy Service"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\HTran
Start = "2"

Proxy Server Routine

This backdoor acts as a proxy server to allow remote malicious user to use the affected systems to hide their identities when performing malicious activities.

Other Details

Based on analysis of the codes, it has the following capabilities:

  • Performs the following:
    • Act as proxy
    • Bind port
    • Connect to target machine
    • Listen to a port
    • Transmit packet to target machine

  SOLUTION

Minimum Scan Engine: 8.900
FIRST VSAPI PATTERN FILE: 7.468.02
FIRST VSAPI PATTERN DATE: 17 Sep 2010
VSAPI OPR PATTERN File: 7.469.00
VSAPI OPR PATTERN Date: 18 Sep 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

Identify and terminate files detected as BKDR_LIONDOOR.I

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. 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.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 3

Delete this registry key

[ 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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • HTran

Step 4

Scan your computer with your Trend Micro product to delete files detected as BKDR_LIONDOOR.I. 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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