grepflag

A grep tool for CTF that will print the flag-like ANYSTRINGS{ANYSTRINGS_NOT_EMPTY}

By: r3dh4ir 🏴‍☠️

Installation

$ sudo ./install.sh

Usage

Running this command will run strings by default if cat output and strings is not equal other wise will print both cat and strings output

$ grepflag file.any

Working with strings

$ strings flag.bin | grepflag

New update working with binary

$ cat flag.img | grepflag -c

For recursive search of matched paired '{}' from a directory use the following command with the -r option

$ grepflag -r directory/

Sample Outputs

$ cat test.txt
asdfasdfasdf
{asdfadsf
adsfasdfas
asdfadsfadsf}
asdfadsf
adsfasdf
{asdfadsfadsf}

With grepflag

$ cat test.txt | grepflag
{asdfadsfadsfasdfasasdfadsfadsf}
{asdfadsfadsf}

Future grepflag project 🚀

Given list of possible flag from grepflag script:

{asdfew3gsdgawewegdse3}
{y0u_f0und_th3_fl4g}

 

Expected output: 

{asdfew3gsdgawewegdse3}            - Entropy Score: 34% but detected as md5 20%
{y0u_f0und_th3_fl4g}               - Entropy Score: 98% flag