🚩 Pico CTF - Nice Netcat

Run the following command.

nc mercury.picoctf.net 35652

returns an output of numbers in decimal format. We have to create a python script in order to convert from this decimal output to ASCII text.

First save the output to a file named flag.txt

nc mercury.picoctf.net 35652 > flag.txt

After that, we need to place the numbers in the same line using awk.

cat flag.txt | awk '{print}' ORS=''

After we got the output in the same line, here is the python script that converts decimal to ASCII text.

def decimal_to_ascii(decimal_str):
    
    string_convert = ""
    for decimal_char in decimal_str.split(" "):
        string_convert += chr(int(decimal_char, 10))
    return string_convert

val = input("Enter decimal format: ")
print(decimal_to_ascii(val))

Name the file decimal.py and run it with the following command. In the prompt enter the decimal numbers.

python3 decimal.py

You got the flag!