Modified by: Mark Joseph Manahan

ALIASES:

W32/Rimecud.Y2.gen!Eldorado (generic, not disinfectable) (Fprot), TR/Crypt.XPACK.Gen3 (Antivir)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003, Windows Vista, Windows 7

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

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

This backdoor arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It does not have any propagation routine.

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

It does not drop any other file.

It does not have any downloading capability.

  TECHNICAL DETAILS

File Size: 53,248 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 02 Nov 2012
Payload: Compromises system security, Connects to URLs/IPs

Arrival Details

This backdoor arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

It 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 adds the following mutexes to ensure that only one of its copies runs at any one time:

  • n888888h1

Autostart Technique

This backdoor adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
windwosseris prof = "{Malware Path}\WinMainPro.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run - for users with Admin Rights
windwosseris prof = "{Malware Path}\WinMainPro.exe"

Propagation

This backdoor does not have any propagation routine.

Backdoor Routine

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

  • Send system information (Lan IP, Wan IP, Computer name, Username, Account Type, OS)
  • Send hardware information (CPU speed, Memory)
  • Manage Files (Search, Download, Upload, Execute, Rename, Delete)
  • Manage Registries (Search, Modify, Delete, Rename, Create)
  • Manage Processes (View, Kill, Suspend, Unload Module)
  • Manage Services (View, Start, Stop, Edit, Install, Uninstall)
  • Manage Devices (View, Enable, Disable, Remove)
  • Manage Windows
  • Relay server
  • View,copy and uninstall applications
  • View active ports
  • Perform a shell command
  • Download and inject remote codes to legitimate processes
  • Log keystrokes and active window
  • Capture screenshots
  • View webcam activity
  • Listen to microphone audio
  • Update, Uninstall, Restart the malware
  • Retrieve cached passwords and hashes

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

  • {BLOCKED}y.{BLOCKED}arleft.com:443
  • hk.{BLOCKED}arleft.com:80

Dropping Routine

This backdoor does not drop any other file.

Download Routine

This backdoor does not have any downloading capability.

NOTES:

It queries the default web browser by accessing the following registry entry:

HKEY_CLASSES_ROOT\http\shell\open\command

It then launches a hidden web browser process (e.g. iexplore.exe). The malware then injects its code if the said process which contains its backdoor routines.

It does not have rootkit capabilities.

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 9.502.04
FIRST VSAPI PATTERN DATE: 02 Nov 2012
VSAPI OPR PATTERN File: 9.505.00
VSAPI OPR PATTERN Date: 04 Nov 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

Restart in Safe Mode

[ Learn More ]

Step 3

Delete this registry value

[ 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\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • windwosseris prof = "{Malware Path}\WinMainPro.exe"
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • windwosseris prof = "{Malware Path}\WinMainPro.exe"

Step 4

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