From Atka Software:
Aura won't let any new program files (including malicious and unwanted software such as adware, viruses, and spyware) onto your computer without your permission. Quite simply, Aura has a patent pending file blocker technology that stops program files from dropping on you computer hard drive just by surfing the Web. It is a simple concept, but very different than what you may be used to. With Aura, you are able to stop all unwanted and malicious files proactively. There is no need to watch for the latest security threat--you are always protected.