ActiveX Controls are easy to create, and hundreds of them already exist on the Web. Some of them could contain viruses, which you don't want to download. Internet Explorer comes with Authenticode, a security technology that enables developers to digitally sign their software code.
A digital signature is like a hologram on a software boxit tells you who created the software and guarantees that it was not tampered with after it left the manufacturer.
When you visit a Web page that has an ActiveX Control, Internet Explorer checks to see if it has been digitally signed. If it hasn't, Internet Explorer displays the following dialog box, which lets you decide whether you want to take a chance and download the control.
If the control has been signed, Internet Explorer displays a certificate such as this one.