Cross Site Scripting is a major vulnerability that is often exploited by hackers for website hacking. It is one of the more difficult vulnerabilities to deal with because of the way it works. Some of the largest websites in the world have dealt with successful XSS attacks including Microsoft and Google. Most XSS website hacking attacks use malicious Javascript scripts that are embedded in hyperlinks. When the user clicks the link, it might steal personal information, hijack a web session, take over a user account, or change the advertisements that are being displayed on a page. Hackers will often insert these malicious links into web forums, social media websites, and other prominent locations where users will click them. To avoid XSS attacks, website owners must filter user input to remove any malicious code.