PWS-Bluedit

This page shows details and results of our analysis on the malware PWS-Bluedit

Overview

This is a trojan detection. Unlike viruses, trojans do not self-replicate. They are spread manually, often under the premise that they are beneficial or wanted. The most common installation methods involve system or security exploitation, and unsuspecting users manually executing unknown programs. Distribution channels include email, malicious or hacked web pages, Internet Relay Chat (IRC), peer-to-peer networks, etc.


Minimum DAT

4466 (2005-04-11)

Updated DAT

5228 (2008-02-12)

Minimum Engine

5.1.00

File Length

46,080

Description Added

2005-04-11

Description Modified

2005-05-31

Malware Proliferation

Characteristics

This is a password stealing trojan that captures the network game account information and sends this information to the author via mail.

When run, it modifies the following registry entries.

  • HKEY_USERS\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Run "IESet" = "IExplorer.dll .dbt"
  • HKEY_USERS\S-1-5-18\Software\Microsoft\Windows\CurrentVersion\Run "IESet" = "IExplorer.dll .dbt"
  • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run "IESet" ="IExplorer.dll .dbt"
  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run "IESet"= "IExplorer.dll .dbt"
  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices "IESet"= "IExplorer.dll .dbt"
  • HKEY_CLASSES_ROOT\.dbt "(Default)" = DBTFILE
  • HKEY_CLASSES_ROOT\DBTFILE "(Default)" =
  • HKEY_CLASSES_ROOT\DBTFILE\shell "(Default)"
  • HKEY_CLASSES_ROOT\DBTFILE\shell\open "(Default)"
  • HKEY_CLASSES_ROOT\DBTFILE\shell\open\command "(Default)" = NOTEDAD.EXE %1
  • HKEY_CLASSES_ROOT\batfile\shell\open\command "(Default)" = NOTEDAD.EXE %1
  • HKEY_CLASSES_ROOT\inifile\shell\open\command "(Default)" = NOTEDAD.EXE %1
  • HKEY_CLASSES_ROOT\regfile\shell\open\command "(Default)" = NOTEDAD.EXE %1
  • HKEY_CLASSES_ROOT\txtfile\shell\open\command "(Default)" = NOTEDAD.EXE %1

The trojan monitors the Chinese network game window and captures username and password. It then attempts to send this information to the author via mail. This trojan creates a mutex named "qfsl ^-^" to ensure that only one instance is run on the victim machine.

Symptoms

The Trojan is running in the process list.

Mails may be sent using Outlook in some instances, or network traffic on port 25, connecting to a remote SMTP (mail) server to send email data to the malware author.

Method of Infection

N/A. Password Stealers are not viruses, and as such do not themselves contain any method to replicate. However they may themselves be downloaded by other viruses and/or Trojans to be installed on the user's system.

Many of these additionally are mass spammed by the author to entice people into double-clicking on them.

Alternatively they may be installed by visiting a malicious web page (either by clicking on a link, or by the website hosting a scripted exploit which installs the Password Stealer onto the user's system with no user interaction.

Removal

All Users:
Use current engine and DAT files for detection and removal.

Modifications made to the system Registry and/or INI files for the purposes of hooking system startup, will be successfully removed if cleaning with the recommended engine and DAT combination (or higher).

But in some particular cases, the following steps need to be taken.

Please go to the Microsoft Recovery Console and restore a clean MBR.

On Windows XP:

  • Insert the Windows XP CD into the CD-ROM drive and restart the computer.
  • When the "Welcome to Setup" screen appears, press R to start the Recovery Console.
  • Select the Windows installation that is compromised and provide the administrator password.
  • Issue 'fixmbr' command to restore the Master Boot Record
  • Follow onscreen instructions.
  • Reset and remove the CD from CD-ROM drive.


On Windows Vista and 7:

  • Insert the Windows CD into the CD-ROM drive and restart the computer.
  • Click on "Repair Your Computer".
  • When the System Recovery Options dialog comes up, choose the Command Prompt.
  • Issue 'bootrec /fixmbr' command to restore the Master Boot Record.
  • Follow onscreen instructions.
  • Reset and remove the CD from CD-ROM drive.

Variants