Adware:Adware (or spyware) is a small program that is designed to show advertisements (in various form and degrees of intrusiveness) on your computer. It often reports personal information back to its owners. As a result your sense of privacy can be violated.
MediaInject is a typical adware spyware that downloads and shows undesirable commercial advertisements based on user surfing habbits. MediaInject tracks user activity in the Internet and sends gathered information to its home server. The adware runs on every Windows startup.
Technical details (How to remove MediaInject(pop up))