Megaupload is a file hosting service on the Internet that is displaying a captcha before the download link of a file will be shown on their website. The captcha is probably one of the easiest to recognize and fill out, pretty useless from the standpoint of defeating bots and annoying to users who download files from Megaupload regularly.

Megaupload auto-fill captcha is a Greasemonkey script for Mozille Firefox (and other compatible browsers) that will automatically fill out and send the captcha on Megaupload. This essentially means that the user does not have to enter the captcha nor click on a button to send it to the Megaupload server.

It practically feels as if there was not a captcha on Megaupload at all. A short explanation of Greasemonkey. Greasemonkey is a Firefox extension that can be installed just like any other extension in Firefox. Once the extension is installed it is possible to add so called userscripts to the web browser.

Those scripts are coded in JavaScript and change the behavior and look and feel of websites automatically.