Reversing PE (Portable Executable)

Last modified: 2024-02-18

Reverse Engineering Windows

The Portable Executable format is a file format for executables, object code, DLLs and others used in 32-bit and 64-bit versions of Windows.

PE Headers

There are many tools to analyze PE headers, such as wxHexEditor, pe-tree.
pe-tree is a tool that views PE files in a tree-view. It will take about a few minutes to open.

pe-tree ./executable
Structure Description
IMAGE_DOS_HEADER It consists of the first 64 bytes of the PE file. The first two bytes (”4D 5A”) means the “MZ” characters which are an identity of the Portable Executable format.
DOS_STUB It is a small piece of code that only runs if the PE file is incompatible with the system it is being run on. At such time the message “!This program cannot be run in DOS mode" will be displayed.
IMAGE_NT_HEADERS It contains most of the vital information related to the PE file. The starting address of the IMAGE_NT_HEADERS is found in e_lfanew from the IMAGE_DOS_HEADER. It contains NT_HEADERS, IMAGE_SECTION_HEADER, IMAGE_IMPORT_DESCRIPTION

Identify Packers of Packed Executable

pecheck is a command-line tool which analyze PE files.

pecheck ./executable

When results appears, check the section name in the PE Section.