What Is a BHO (Browser Helper Object) Add On?

A BHO, or browser helper object, is a component of Microsoft's Internet Explorer web browser application. It is an add-in designed to provide or expand the functionality of the browser and allow developers to improve the web browser with new features.

BHOs, in and of themselves, are not bad, but like a lot of other features and functionality, if the BHO can be used to install additional features or functions that are useful, it can also be exploited to install features or functions that are malicious. Some applications, such as the Google or Yahoo toolbars, are examples of good BHO's, but, there are also many examples of BHO's that are used to hijack your web browser homepage, spy on your internet activities and other malicious actions.

With Windows XP SP2 installed, you can view the BHOs that are currently installed in Internet Explorer by clicking on Tools, then Manage Add-Ons. Microsoft's anti-spyware utility and some other tools such as BHODemon can be used to detect and remove malicious BHOs.

If you are concerned about bad BHO's and their effect on the overall security of your computer, you can switch browsers. BHO's are unique to Microsoft's Internet Explorer and do not impact other web browser applications, such as Firefox.

If you plan to continue using Internet Explorer but want to protect yourself from malicious BHOs, you can run BHODemon, which has a real-time monitoring component or an anti-spyware application that has a real-time monitoring component to detect and block bad BHOs actively. You can also periodically click on Tools > Manage Add-Ons to ensure no suspicious or malicious BHOs have been installed without your knowledge.