McAfee Secure sites help keep you safe from identity theft, credit card fraud, spyware, spam, viruses and online scams
Business Home → McAfee Labs → Threat Intelligence

BackDoor-CHN.gen

This page shows details and results of our analysis on the malware BackDoor-CHN.gen

Threat Detail

Malware Type: Trojan

Malware Sub-type: Generic

Discovery Date: 2004-11-10

Next Steps:

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

4397 (2004-10-06)

Updated DAT

4406 (2004-11-10)

 Minimum Engine

5.1.00

File Length

Varies

 Description Added

2004-10-06

Description Modified

2004-11-12

Malware Proliferation

Characteristics

There are several variants of this trojan.  This text describes one recent variant, which was recently installed via an HTML page that contained the Exploit-IframBO trojan.  Navigating to a malicious site hosting this webpage resulted in vulnerable Internet Explorer web browsers executing download code, which downloaded and executed BackDoor-CHN.gen.  This variant is detected with the 4397 DAT files (and higher).

When run, the BackDoor trojan copies itself to the WINDOWS and WINDOWS SYSTEM directories and creates 2 registry run keys to load itself at system startup:

  • C:\WINDOWS\winuser.exe
  • C:\WINDOWS\system32\userhandler.exe

  • HKEY_CURRENT_USER\Software\Microsoft\Windows NT\
    CurrentVersion\Windows "run" = C:\WINDOWS\winuser.exe
  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\
    CurrentVersion\Run "UserHandler" = C:\WINDOWS\system32\userhandler.exe

The trojan attempts to notify websites of the infected systems IP address:

  • http://vb-aus.com/datauk.php ?
  • http://67.15.72.14/datauk.php ?
  • http://puterpaul.co.uk/datauk.php ?
  • http://vb-aus.com/alertuk.php?alert
  • http://67.15.72.14/alertuk.php?alert
  • http://puterpaul.co.uk/alertuk.php?alert

The trojan also monitors Internet Explorer usage in an attempt to steal account information.  It particularly looks for the following website Titles and URLs

  • Barclays IBank
  • HSBC Internet Banking
  • Equifax UK Commercial
  • Experian candidate verifier
  • LloydsTSB online - Welcome
  • Enter memorable information
  • NatWest OnLine Banking
  • Online Service
  • Transfer to another organisation - Create
  • Nationwide Building Society - Internet banking
  • Login
  • Abbey
  • Egg Security Login
  • Digital Banking
  • welcome to smile banking
  • Scotia OnLine Sign-On
  • Citibank Internet Banking
  • iBill Payment Page
  • CCBill Secure Signup Form
  • Logon
  • anking
  • https://ibank.barclays.co.uk/fp/
  • https://ibank.barclays.co.uk/fp/
  • https://www.ebank.hsbc.co.uk/logonindex.jsp
  • http://www.candidateverifier.com/
  • https://www.equifax.co.uk/equifax/commercial/index.html
  • https://online.lloydstsb.co.uk/customer.ibc
  • https://online.lloydstsb.co.uk/logon.ibc
  • https://online-business.lloydstsb.co.uk/customer.ibc
  • https://online-business.lloydstsb.co.uk/logon.ibc
  • https://www.nwolb.com/secure/default.asp
  • https://www.nwolb.com/secure/logon.asp
  • Logon-PinPass.asp
  • https://www.halifax-online.co.uk/_mem_bin/formslogin.asp
  • https://banking.halifax-online.co.uk/Servicing/App/CreateBillPayment.asp
  • https://olb2.nationet.com/default
  • https://www.natwestfastpay.com/service/default.jsp?
  • https://myonlineaccounts2.abbeynational.co.uk/ffStatic/html/logon.html
  • https://myonlineaccounts2.abbeynational.co.uk/CentralLogonWeb/Logon?action=prepare
  • https://new.egg.com/security/customer/logon?URI=https://new.egg.com/customer/youraccounts
  • https://www.rbsdigital.com/secure/default.asp?refererident=
  • Logon.asp
  • https://welcome3.smile.co.uk/servlet/Smile5Banking
  • https://www.scotiaonline.scotiabank.com/online/start.jsp?language=
  • https://secure.ibill.com/cgi-win/ccard/ccard.exe
  • https://bill.ccbill.com/jpost/signup.cgi
  • https://cukehb2.cd.citibank.co.uk/HomeBankingSecure/Pers/StartSession.asp
  • https://www1.net.hsbc.com/code/public/en_US/login/poplogin.jhtml
  • https://

Symptoms

Presence of the aforementioned files and registry keys.

Method of Infection

Trojans do not self-replicate. They are spread manually, often under the premise that the executable is something beneficial. Distribution channels include IRC, peer-to-peer networks, newsgroup postings, etc

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

United States - English