Run Program from byte array

Question

I have a program stored in byte array.

Is it possible to run it inside C#?

Answer 1

Yes. This answer shows you can directly execute the contents of a byte array. Basically, you use VirtualAlloc to allocate an executable region on the heap with a known address (a IntPtr). You then copy your byte array to that address with Marshal.Copy. You convert the pointer to a delegate with GetDelegateForFunctionPointer, and finally call it as a normal delegate.

Answer 2

Sure.

1. Save the byte array to an .exe file.
2. Use the Process class to execute the file.

Note: this is assuming that your byte array is executable code, and not source code. This also assumes that you have a valid PE header or know how to make one.

Answer 3

Assuming the byte array contains a .net assembly (.exe or .dll):

 Assembly assembly = AppDomain.Load(yourByteArray)
 Type typeToExecute = assembly.GetType("ClassName");
 Object instance = Activator.CreateInstance(typeToExecute);

Now, if typeToExecute implements an interface known to your calling program, you can cast it to this interface and invoke methods on it:

 ((MyInterface)instance).methodToInvoke();

Answer 4

If the byte array is a .Net assembly with an EntryPoint (Main method) you could just do this. Most of the time returnValue would be null. And if you wanted to provide command line arguments you could put them in the commandArgs string listed below.

var assembly = Assembly.Load(assemblyBuffer);
var entryPoint = assembly.EntryPoint;
var commandArgs = new string[0];
var returnValue = entryPoint.Invoke(null, new object[] { commandArgs });