Prevent your browser from being hijacked by unwanted ads

Your browser is behaving strangely. It crashes and closes all other programs. Soon advertisements begin to pop up on your desktop… These are signs of 'browser hijacking', a sneaky method to watch your online activity and drown you in ads.

Companies trying to make a quick buck at your expense have been releasing such browser hijacking programs, usually referred to as spyware and adware. These programs change your browser settings, dictate your surfing patterns and bombard you with advertisements.

Here's a guide that will help you avoid a browser hijack:

How browser hijacking works

It all begins with malicious software being installed on your machine without you being aware of it. Often, the rogue code gets on to a victim's machine in a 'drive-by download'. This is a download that happens while you are surfing and goes unnoticed.

Most often the unwanted software begins by changing your browser's default homepage to a page that the hijacker wants to direct traffic to. These programs can also add new shortcuts to your browser's 'Favourites' list.

From now on, the hijacking code keeps track of your surfing habits by noting the sites you visit. And without your knowledge, the program sends this information across the Internet to the server of the hijacking company that unleashed it.

The company then uses this data to swamp you with ads, links and pop-ups, all hawking products they have been paid to push.

An example of browser hijacking is the Xupiter toolbar. It works like this:

• The Xupiter code installs itself as an extra toolbar on you browser
• It changes your default homepage automatically
• It adds gaming and adult links to your favourites menu
• And to top it all, it causes frequent browser crashes

Although there are official uninstallers available for the Xupiter toolbar, they are ineffective. This is because Xupiter makes multiple entries for itself in your computer's registry in a bid to dodge attempts at uninstallation.

Another example of spyware is Gator; also known as GAIN (Gator Advertising and Information Network). It works along the same lines as Xupiter but doesn't cause as much damage and its removal instructions can be found here.

Stony Brook University has compiled a good list of problematic software.

How to prevent hijacking?

1. Keep your anti-virus definitions updated. Install firewall and anti-spyware software on your system.
2. Avoid opening email attachments from anonymous users.
3. Avoid using file-sharing software.
4. Don't download software that has no description of the company or the developer.
5. Scan your system for viruses, weekly or fortnightly.
6. Always send mail attachments after scanning the file.
7. Always read the fine print before installing anything that is offered to you while surfing.
8. Read the End User's License Agreement (EULA) carefully. They usually mention somewhere in fine print that your data will be shared with companies.
9. Increase your browser's security settings by disabling ActiveX that is not signed or safe.
10. Apply Windows security updates provided by Microsoft.

A host of software that can detect spyware are also available.

Spyware Blaster: Once installed, it prohibits the installation of any spyware software and denies access to any malicious ActiveX code included in its list.

Browser Hijack Blaster: Protects your system from browser hijackers and spyware that alters your Internet Explorer settings.

Ad-aware: Awarded the best software product of 2002 by PC World Magazine, this application scans the system memory and registry to detect data-mining, advertising and malicious codes.