Generic StartPage.l

This page shows details and results of our analysis on the malware Generic StartPage.l

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

4534 (2005-07-13)

Updated DAT

6433 (2011-08-09)

Minimum Engine

5400.1158

File Length

varies

Description Added

2005-07-13

Description Modified

2006-02-19

Malware Proliferation

Characteristics

This is a generic detection for start page trojans.

These Trojans can be installed via a wide variety of means - utilizing vulnerabilities in browsers, dropped by other viruses etc.

They are designed to replace the user's web browser start page, typically to generate revenue for the author by increasing the number of times the advertisments on their page are displayed (also known as "impressions", an advertisement which is displayed to a user, but not necessarily clicked on) and also the probability that any of the ads might then be clicked by the user. This is designed to make the Trojan author money from a "pay per impression" or "pay per click" scheme. The redirected start page location could also utilize exploits or contain automatic download prompting to install other software.

McAfee writes more generic detections for these threats and to proactively protect customers against future minor variants. Therefore it is not possible to specify which website will be communicated with for a given detection.

Symptoms

This is a generic detection so specific details are not possible. The Trojan will usually install itself into %windir% or %systemdir% and create a registry key to cause it to launch on restart. The system may also be attempt to connect to the Internet on startup.

Generally start page trojans modify one or more of the following keys.

  • HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main\Search Page
  • HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main\Start Page
  • HKEY_CURRENT_USER\Software\Microsoft\Windows\currentversion\run
    Default_Page_URL
  • HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer\Main\Search Page
  • HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer\Main\Start Page
  • HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\currentversion\run
    Default_Page_URL

In effect, changing these keys will modify the default web page which loads when the Internet browser is launched, and change the default search behavior.

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.

Start page hijackers are not viruses, and as such do not themselves contain any method to replicate. However they may be downloaded by other viruses and/or Trojans to be installed on the user's system. Many of these are mass spammed by the author to entice people into double-clicking on them. Alternately 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 Trojan 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