exe2hex

Inline file transfer using in-built Windows tools (debug.exe or PowerShell).

Overview

exe2hex encodes an executable binary file into ASCII text format.

The result then can be transferred to the target machine (It is much easier to echo a ASCII file than binary data).

Upon executing exe2hex's output file, the original program is restored by using DEBUG.exe or PowerShell (which are pre-installed by default).

Binary EXE -> ASCII Text -> *Transfer* -> Binary EXE

Quick Guide

• Input using a file (-x /path/to/binary-program.exe) or STDIN (-s)
• Output to BATch (-b file.bat) and/or PoSH (-p powershell.cmd)

Example Usage

$ python3 exe2hex.py -x /usr/share/windows-binaries/sbd.exe
[*] exe2hex v1.3
[i] Outputting to /root/sbd.bat (BATch) and /root/sbd.cmd (PoSh)
[+] Successfully wrote (BATch) /root/sbd.bat
[+] Successfully wrote (PoSh) /root/sbd.cmd
$

$ ./exe2hex.py -x /usr/share/windows-binaries/nc.exe -b /var/www/html/nc.txt -cc
[*] exe2hex v1.3
[i] Attempting to clone and compress
[i] Creating temporary file /tmp/tmpkel8b4f0
[+] Compression (strip) was successful! (0.0% saved)
[+] Compression (UPX) was successful! (50.9% saved)
[+] Successfully wrote (BATch) /var/www/html/nc.txt
$

$ cat /usr/share/windows-binaries/whoami.exe | python exe2hex.py -s -b debug.bat -p ps.cmd
[*] exe2hex v1.3
[i] Reading from STDIN
[+] Successfully wrote (BATch) /root/debug.bat
[+] Successfully wrote (PoSh) /root/ps.cmd
$

Help

$ python3 exe2hex.py -h
[*] exe2hex v1.3
Usage: exe2hex.py [options]

Options:
  -h, --help  show this help message and exit
  -x EXE      The EXE binary file to convert
  -s          Read from STDIN
  -b BAT      BAT output file (DEBUG.exe method - x86)
  -p POSH     PoSh output file (PowerShell method - x86/x64)
  -e          URL encode the output
  -r TEXT     pRefix - text to add before the command on each line
  -f TEXT     suFfix - text to add after the command on each line
  -l INT      Maximum HEX values per line
  -v          Enable verbose mode
  -c          Clones and compress the file before converting (-cc for higher
              compression)
$

Methods/OS Support

• DEBUG.exe (BATch mode - -b)
  • Supports x86 OSs (No x64 support).
  • Useful for legacy versions of Windows (e.g. Windows XP/Windows 2000).
    • Pre-installed by default. Works out of the box.
  • Limitation of 64k file size for binary programs. Creates multiple parts and joins with copy /b so this is not an issue any more!
• PowerShell (PoSh mode - -p)
  • Supports both x86 & x64 OSs.
  • Aimed at more "recent" versions of Windows.
    • PowerShell was first integrated into core OS with Windows 7/Windows Server 2008 R2.
    • Windows XP SP2, Windows Server 2003 & Windows Vista requires PowerShell to be pre-installed.
  • This is not a .ps1 file (pure PowerShell). It only calls PowerShell at the end to convert.

Features

Primary purpose: Convert a binary program into a ASCII HEX file which can be restored using in-built OS programs.

• Able to use a file or standard input
• Work on old and new versions of Windows without any 3rd party programs.
• Supports x86 & x64.
• Includes a function to compress the file.
• URL encode the output.
• Option to add prefix and suffix text to each line.
• Able to set a maximum HEX length.

Note: This is nothing new. The core idea has been around since 2003 (if not before!).