Having a source code might help you in skipping the first step(decompile and disassemble), but you have to perform step 2 and 3 to analyse the behaviour of the

Having a source code might help you in skipping the first step(decompile and disassemble), but you have to perform step 2 and 3 to analyse the behaviour of the program. You might have to perform step 1 , if the source code had compiled third party libraries, which might contain hidden routines to perform malicious operations (such as decryption).