Analysis by: Cris Nowell Pantanilla
 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

Infection Channel: Downloaded from the Internet, Dropped by other malware

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 executes then deletes itself afterward. It may be injected into processes running in memory.

It connects to a website to send and receive information.

It executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

  TECHNICAL DETAILS

Ports: TCP Port 443
File Size: 208,896 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 30 Aug 2012
Payload: Connects to URLs/IPs

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 executes then deletes itself afterward.

It may be injected into processes running in memory.

Backdoor Routine

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

  • {BLOCKED}upd.at/first.php?r{value}
  • {BLOCKED}vise.cc/first.php?r{value}
  • {BLOCKED}in.su/first.php?r{value}

It posts the following information to its command and control (C&C) server:

  • Installed Applications
  • Directory and File List
  • Drive Informations
  • Network Information
  • Username
  • Computername
  • OS Version
  • Hardware Information
  • Running Processes

Dropping Routine

This backdoor drops the following files:

  • %User Temp%\{random}.exe

(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.)

It executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

  SOLUTION

Minimum Scan Engine: 9.200

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

Scan your computer with your Trend Micro product and note files detected as BKDR_DYCLER.AD

Step 3

Restart in Safe Mode

[ Learn More ]

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%\{random}.exe

Step 5

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