mirror of https://github.com/sqall01/LSMS.git
159 lines
4.1 KiB
Python
Executable File
159 lines
4.1 KiB
Python
Executable File
#!/usr/bin/env python3
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# written by sqall
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# twitter: https://twitter.com/sqall01
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# blog: https://h4des.org
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# github: https://github.com/sqall01
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#
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# Licensed under the MIT License.
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"""
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Short summary:
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Monitor /etc/hosts for changes to detect malicious attempts to divert traffic.
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Requirements:
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None
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"""
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import os
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from typing import Dict, Set
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from lib.state import load_state, store_state
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from lib.util import output_error, output_finding
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# Read configuration.
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try:
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from config.config import ALERTR_FIFO, FROM_ADDR, TO_ADDR, STATE_DIR
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from config.monitor_hosts_file import ACTIVATED
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STATE_DIR = os.path.join(os.path.dirname(__file__), STATE_DIR, os.path.basename(__file__))
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except:
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ALERTR_FIFO = None
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FROM_ADDR = None
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TO_ADDR = None
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ACTIVATED = True
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STATE_DIR = os.path.join("/tmp", os.path.basename(__file__))
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class MonitorHostsException(Exception):
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def __init__(self, msg: str):
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self._msg = msg
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def __str__(self):
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return self._msg
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def _get_hosts() -> Dict[str, Set[str]]:
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hosts_data = {}
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with open("/etc/hosts", 'rt') as fp:
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for line in fp:
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line = line.strip()
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if line == "":
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continue
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# Ignore comments.
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if line[0] == "#":
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continue
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entry = line.split()
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if len(entry) < 2:
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raise MonitorHostsException("Not able to parse line: %s" % line)
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ip = entry[0]
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hosts = set(entry[1:])
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if ip not in hosts_data.keys():
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hosts_data[ip] = hosts
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else:
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for host in hosts:
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hosts_data[ip].add(host)
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return hosts_data
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def monitor_hosts():
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# Decide where to output results.
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print_output = False
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if ALERTR_FIFO is None and FROM_ADDR is None and TO_ADDR is None:
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print_output = True
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if not ACTIVATED:
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if print_output:
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print("Module deactivated.")
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return
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stored_hosts_data = {}
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try:
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state_data = load_state(STATE_DIR)
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# Convert list to set.
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for k, v in state_data.items():
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stored_hosts_data[k] = set(v)
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except Exception as e:
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output_error(__file__, str(e))
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return
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curr_hosts_data = {}
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try:
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curr_hosts_data = _get_hosts()
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except Exception as e:
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output_error(__file__, str(e))
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return
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# Compare stored data with current one.
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for stored_entry_ip in stored_hosts_data.keys():
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# Extract current entry belonging to the same ip.
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if stored_entry_ip not in curr_hosts_data.keys():
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message = "Host name for IP '%s' was deleted." % stored_entry_ip
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output_finding(__file__, message)
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continue
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# Check host entry was removed.
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for host in stored_hosts_data[stored_entry_ip]:
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if host not in curr_hosts_data[stored_entry_ip]:
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message = "Host name entry for IP '%s' was removed.\n\n" % stored_entry_ip
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message += "Entry: %s" % host
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output_finding(__file__, message)
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# Check host entry was added.
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for host in curr_hosts_data[stored_entry_ip]:
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if host not in stored_hosts_data[stored_entry_ip]:
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message = "Host name entry for IP '%s' was added.\n\n" % stored_entry_ip
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message += "Entry: %s" % host
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output_finding(__file__, message)
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# Check new data was added.
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for curr_entry_ip in curr_hosts_data.keys():
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if curr_entry_ip not in stored_hosts_data.keys():
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message = "New host name was added for IP '%s'.\n\n" % curr_entry_ip
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message += "Entries:\n"
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for host in curr_hosts_data[curr_entry_ip]:
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message += host
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message += "\n"
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output_finding(__file__, message)
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try:
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# Convert set to list.
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state_data = {}
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for k, v in curr_hosts_data.items():
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state_data[k] = list(v)
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store_state(STATE_DIR, state_data)
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except Exception as e:
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output_error(__file__, str(e))
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if __name__ == '__main__':
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monitor_hosts()
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