Support article

Summary

This article describes how you can remove Classloader Exploit and other Internet Explorer trojans. Also, the article provides suggestions on how to avoid future infections.

Problem description

Classloader and other trojans utilize unpatched bugs in Internet Explorer to infect the computer. A simple way to reduce the likelihood of your computer being infected is to keep its software up to date.

Solution

The solution for classloader exploits and similar software is to update Internet Explorer, clear the temporary internet files and then re-scan the computer.

For Internet Explorer and other Microsoft software, the easiest way to keep your computer up to date is to use Microsoft Update:

1. Open page http://update.microsoft.com/ .
2. Select all available updates.
3. Windows update will install updates and may request you to restart your computer.

Removing infection

If F-Secure detects infected files inside Internet Explorer cache folders, we recommend that you empty them completely. Since the files in these folders are only cached copies, no actual data is lost in this operation.

For instructions on how to clear the temporary files in Internet Explorer, see article 2237 - Cleaning temporary Internet files in Internet Explorer .

More information

More details about the Classloader can be found at http://www.f-secure.com/v-descs/classloader.shtml .

Microsoft's article on how to configure automatic updates in Windows XP: http://support.microsoft.com/kb/306525 .