wssecure Application Monitor is a program for Windows that can be used to detect unknown viruses and spyware that are often installed through remote exploits and unpatched vulnerabilities. It allows the user to trust programs (processes) initially and prompts when they are modified and when new programs run in the computer. It also contains a registry monitor to immediately notify the user when new programs get added to the start up section.
An add-on for wssecure can be downloaded freely from http://bapuli.reflectionsindia.org that blocks new programs that are not in the trusted list from running.