Decompiling EXE to ASM

Question

I want to make a basic antivirus for my free time. Basically I learned about the basic structure of the EXE(windows) file. How do I extract the ASM code from the file and the PE header?

Solution 1

You can install Cygwin and use objdump to decompile an exe into asm. Be sure you select the binutils when installing cygwin. After installing cygwin, you can run the following from a bash shell:

objdump -Slx yourpgm.exe

Solution 2

You can use some free distrubuted disassembler.for example: ollydbg diassembler.

note: there is only some MS-DOS stub executeable code in the PE header.

Comments

[zxcat]

Yes, or run Linux on Virtual Machine and use objdump there. Sounds like a black humor ;)

[j_kubik]

"there is only some MS-DOS stub executeable code in the PE header." And what if there isn't? You never know where virus will choose to hide, and headers are also loaded to memory, right?