A data source object (DSO) is a Microsoft ActiveX object embedded within a Web page. It employs a process called data binding, in which an ActiveX control communicates directly with another Web page, or with an external XML data source.
In order to take advantage of DSOs, it is necessary to have Internet Explorer version 4.0 or later. Web developers commonly create their own DSOs. For example, an animated weather radar image from the National Hurricane Center can be displayed continuously on the home page of a municipal civil defense department, without the need for clicking on a link to get to the National Hurricane Center site.
Data source objects are sometimes used for the purpose of implementing spyware. This type of intrusion shows up on spyware detection programs as a DSO exploit. Such spyware can be difficult to eradicate, and if it is successfully removed, it often returns.