I'd like to ask for your advice about improving security of executing a compiled program on a client's computer. The idea is that we send a compiled program to a client but the program has been written and compiled by a third-party. How to make sure that the program won't make any harm to a client's operating system while running? What would be the best to achieve that goal and not decrease dramatically performance of executing a program?
UPDATE:
I assume that third-party don't want to harm client's OS but it can happen that they make some mistake or their program is infected by someone else.
The program could be compiled to either bytecode or native, it depends on third-party.
Depending on the language involved and what kind of permissions are required, you may be able to use the language's built in sandboxing capabilities. For example, earlier versions of .NET have a "Trust Level" that can be set to control how much access a program has when it's run (newer versions have a similar feature called Code Access Security (CAS)). Java has policy files that control the same thing.
Another method that may be helpful is to run the program using (Microsoft) Sysinternals process monitor, while scanning all operations that the program is doing.
If it's developed by a third party, then it's very difficult to know exactly what it's going to do without reviewing the code. This may be more of a contractual solution - adding penalties into the contract with the third-party and agreeing on their liability for any damages.