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README.md

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+![GitHub release (latest by date)](https://img.shields.io/github/v/release/Silva97/pei)
+
+# pei - PE Injector
+Command-line tool for inject code and manipulate PE32 (32-bit) and PE32+ (64-bit) executables.  
+
+With `pei` you can:
+- Display informations about the executable like COFF header, sections and more.
+- Get individual values from fields of the headers to manipulate the values by scripts. Example:  
+  `pei get test.exe optional.entry_point '0x%x'` - Will print `0x12345`
+- Manipulate memory access permissions to sections of the executable.
+- Find zeroed blocks of data on the sections of the executable.
+- Inject code to be executed before the OEP of the executable.
+
+## Compilation
+Just run the commands below to compile the project:
+```bash
+git clone https://github.com/Silva97/pei
+cd pei
+make
+```
+
+Done! `pei` has no dependencies other than libc.
+
+# How it injects code
+With `pei` you can specify the section to inject the code or leave the tool to select the
+section with the biggest zeroed block of data. You can run `pei z test.exe` to gets a list of
+blocks from all sections of the executable.  
+The entry point of the executable will be updated to point the injected code, and at end of the
+code a [absolute jump] to OEP (Original Entry Point) will be added.
+
+**Note**: After `pei` writes the code on the section, these as been marked with permission to
+execute code and the dynamic base of the executable will be disabled.
+
+# Basic Usage
+```bash
+pei [options] <operation> <executable> [argument]
+```
+
+|   Argument   | Descrption                                                       |
+| :----------: | :--------------------------------------------------------------- |
+| `operation`  | First letter or full name of the operation to do with executable |
+| `executable` | PE32 or PE32+ executable                                         |
+
+**Note**: You can run `pei -h` to get full help about usage of the tool.  
+
+
+
+### Examples
+```bash
+pei s test.exe         # Show general informations about the executable
+pei -vs0 s test.exe s  # Show first section in verbose mode
+pei s test.exe d       # Show all data directories
+pei s test.exe gc      # Show general informations and COFF header
+
+pei g test.exe optional.entry_point '%x'         # Entrypoint in hexadecimal
+pei g test.exe optional.iat.virtual_address '%x' # Virtual address of IAT structure
+pei g test.exe section.0.name '%s'               # Name of the first section
+
+# Inject code from `payload` raw binary file to `test.exe` entry point
+pei -f payload i test.exe
+```
+
+**Tip 1**: For see the name of the fields to use with `get` operation, just use `show` operation
+to see all fields of the given structure. Example:
+
+```bash
+pei show test.exe o
+```
+
+After run the command above, you can see all (except data directories) fields of the optional header.  
+
+**Tip 2**: Remember that the data directories are in the optional header.
+
+
+[absolute jump]: https://en.wikipedia.org/wiki/JMP_(x86_instruction)