Threat description



Needy is a Java applet based trojan that changes the Internet Explorer start page changes search settings to ones contained in the trojan and downloads a trojan downloader. Needy activates when user views a web page or HTML E-mail that contains reference to the trojan file.


Update you Internet Explorer using Windows update to prevent any further infections.

  • 1. Open
  • 2. Select all available updates
  • 3. Windows update installs updates and reboots
  • 4. Return to the Windows updates to make sure you have all updated

Clear the Internet Explorer temporary file cache

  • 1. Open Internet Explorer
  • 2. Select "Tools"->"Internet Options..." from the top menu
  • 3. Select "General" tab (this should be visible already).
  • 4. Click from "Temporary Internet files" pane button "Delete Files..."
  • 5. Select checkbox "Delete all offline content"
  • 6. Click "OK"

Scan your computer with F-Secure Anti-Virus to remove any other downloaded components.

Technical Details

The Needy.C is activated when a web site containing the trojan is loaded with unpacthed Microsoft Internet Explorer browser. When the JAR file containing the trojan is executed it uses Microsoft Internet Explorer VerifierBug vulnerability to get full privileges by escaping the Java security, and execute its code.

When executed the trojan modifies the Internet Explorer start page to point to the site where the trojan is downloaded from, and changes search settings to point to pornographic services.

In addition to changing the Internet Explorer settings the trojan downloads trojan downloader win32.barlf and executes it.


Detection in F-Secure Anti-Virus was published on January 29th, 2004 in update:

Detection Type: PC

Database: 2003-01-29_01

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