IisShield is an IIS isapi filter preventing any known and unknown attacks from disrupting IIS. The preventive approach of IisShield is an added value preventing IIS from even trying to interpret requests trying to break-in. With a detailed logging engine, IisShield helps IIS administrators to know in advance and protect IIS from known or unknown HTTP attacks that flow over the Internet.
The configuration is quite detailed giving the ability to precisely decide over what is accepted and what is not regarding the HTTP Layer. RFC Compliance is just one of the core features of IisShield offering an assurance of quality of service to the IIS Administrator.
IisShield runs in IIS 4.0, IIS 5.x and IIS 6.0.
IisShield is Freeware
Download: IisShield 2.2.1