With a debugger you can step through the program assembly interactively. With a disassembler, you can view the program assembly in more detail. With a decompiler, you can turn a program back into partial source code, assuming you know what it was written in (which you can find out with free tools such as - if the program is packed, you'll have to unpack it first OR if you can't find PEiD anywhere. DIE has a strong developer community on currently). Debuggers: •, free, a fine 32-bit debugger, for which you can find numerous user-made plugins and scripts to make it all the more useful.
Oct 2, 2007 - For this reason you should regard the compiled exe as being encoded. So how about decompiling passphrase protected AutoIt malware?
•, free, a quite capable debugger by Microsoft. WinDbg is especially useful for looking at the Windows internals, since it knows more about the data structures than other debuggers. •, SICE to friends. Commercial and development stopped in 2006. SoftICE is kind of a hardcore tool that runs beneath the operating system (and halts the whole system when invoked). SoftICE is still used by many professionals, although might be hard to obtain and might not work on some hardware (or software - namely, it will not work on Vista or NVIDIA gfx cards).