Analysis by: Cris Nowell Pantanilla
 Modified by: Kathleen Notario
ALIASES:

Backdoor.Win32.Small.khm (Kaspersky); W32/Hupig.B!tr.bdr (Fortinet)

 PLATFORM:

Windows 2000, Windows XP, Windows 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 arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It may be injected into processes running in memory.

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

  TECHNICAL DETAILS

File Size: 15,872 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 09 Sep 2011
Payload: Steals information

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 may be injected into processes running in memory.

Backdoor Routine

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

  • download file
  • execute file
  • execute command shell (cmd.exe)
  • kill process

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

  • *.dyndns.org

NOTES:

It also connects to the mentioned URL to report system infection and send system information such as:

  • hostname
  • ip address
  • language
  • machine name
  • OS name
  • proxy server
  • system time
  • username

Note that the language and proxy server information that it sends is hard-coded.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.416.02
FIRST VSAPI PATTERN DATE: 09 Sep 2011

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

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