Is it possible to write an antivirus program in Java such as that it can intercept a program from being executed? Can I have such a deep control of the OS in Java?
update: what about c#? same restrictions apply or that is a better way?
Having such influence on the OS is possible. There is only the problem, that you will lose the platform independency or at least have to write the code for every given platform due to the reason that such actions require quite deep access of the system which could be achived with JNI, which would tie the method you use it in to the OS.