fae904ec48
The columns tx_host and rx_host have been renamed. This commit reflects the name change and repairs the analysis process.
479 lines
25 KiB
Python
479 lines
25 KiB
Python
|
|
#!/usr/bin/env python3
|
|
# -*- coding: utf-8 -*-
|
|
|
|
from classes.parsezeeklogs import ParseZeekLogs
|
|
from netaddr import IPNetwork, IPAddress
|
|
from utils import get_iocs, get_config, get_whitelist
|
|
from datetime import datetime
|
|
import subprocess as sp
|
|
import json
|
|
import pydig
|
|
import os
|
|
import re
|
|
import sys
|
|
import whois
|
|
|
|
|
|
class ZeekEngine(object):
|
|
|
|
def __init__(self, capture_directory):
|
|
self.working_dir = capture_directory
|
|
self.alerts = []
|
|
self.conns = []
|
|
self.ssl = []
|
|
self.http = []
|
|
self.dns = []
|
|
self.files = []
|
|
self.whitelist = []
|
|
|
|
# Get analysis and userlang configuration
|
|
self.heuristics_analysis = get_config(("analysis", "heuristics"))
|
|
self.iocs_analysis = get_config(("analysis", "iocs"))
|
|
self.whitelist_analysis = get_config(("analysis", "whitelist"))
|
|
self.active_analysis = get_config(("analysis", "active"))
|
|
self.userlang = get_config(("frontend", "user_lang"))
|
|
|
|
# Retreive IOCs.
|
|
if self.iocs_analysis:
|
|
self.bl_cidrs = [[IPNetwork(cidr[0]), cidr[1]]
|
|
for cidr in get_iocs("cidr")]
|
|
self.bl_hosts = get_iocs("ip4addr") + get_iocs("ip6addr")
|
|
self.bl_domains = get_iocs("domain")
|
|
self.bl_freedns = get_iocs("freedns")
|
|
self.bl_nameservers = get_iocs("ns")
|
|
self.bl_tlds = get_iocs("tld")
|
|
|
|
# Retreive whitelisted items.
|
|
if self.whitelist_analysis:
|
|
self.wl_cidrs = [IPNetwork(cidr) for cidr in get_whitelist("cidr")]
|
|
self.wl_hosts = get_whitelist("ip4addr") + get_whitelist("ip6addr")
|
|
self.wl_domains = get_whitelist("domain")
|
|
|
|
# Load template language
|
|
if not re.match("^[a-z]{2,3}$", self.userlang):
|
|
self.userlang = "en"
|
|
with open(os.path.join(os.path.dirname(os.path.realpath(sys.argv[0])), "locales/{}.json".format(self.userlang))) as f:
|
|
self.template = json.load(f)["alerts"]
|
|
|
|
def fill_dns(self, dir):
|
|
"""
|
|
Fill the DNS resolutions thanks to the dns.log.
|
|
:return: nothing - all resolutions appended to self.dns.
|
|
"""
|
|
if os.path.isfile(os.path.join(dir, "dns.log")):
|
|
for record in ParseZeekLogs(os.path.join(dir, "dns.log"), output_format="json", safe_headers=False):
|
|
if record is not None:
|
|
if record["qtype_name"] in ["A", "AAAA"]:
|
|
d = {"domain": record["query"],
|
|
"answers": record["answers"].split(",")}
|
|
if d not in self.dns:
|
|
self.dns.append(d)
|
|
|
|
def netflow_check(self, dir):
|
|
"""
|
|
Enrich and check the netflow from the conn.log against whitelist and IOCs.
|
|
:return: nothing - all stuff appended to self.alerts
|
|
"""
|
|
max_ports = get_config(("analysis", "max_ports"))
|
|
http_default_port = get_config(("analysis", "http_default_port"))
|
|
|
|
# Get the netflow from conn.log.
|
|
if os.path.isfile(os.path.join(dir, "conn.log")):
|
|
for record in ParseZeekLogs(os.path.join(dir, "conn.log"), output_format="json", safe_headers=False):
|
|
if record is not None:
|
|
c = {"ip_dst": record["id.resp_h"],
|
|
"proto": record["proto"],
|
|
"port_dst": record["id.resp_p"],
|
|
"service": record["service"],
|
|
"alert_tiggered": False}
|
|
if c not in self.conns:
|
|
self.conns.append(c)
|
|
|
|
# Let's add some dns resolutions.
|
|
for c in self.conns:
|
|
c["resolution"] = self.resolve(c["ip_dst"])
|
|
|
|
# Order the conns list by the resolution field.
|
|
self.conns = sorted(self.conns, key=lambda c: c["resolution"])
|
|
|
|
# Check for whitelisted assets, if any, delete the record.
|
|
if self.whitelist_analysis:
|
|
|
|
for i, c in enumerate(self.conns):
|
|
if c["ip_dst"] in [ip for ip in self.wl_hosts]:
|
|
self.whitelist.append(self.conns[i])
|
|
self.conns[i] = False
|
|
elif c["resolution"] in self.wl_domains:
|
|
self.whitelist.append(self.conns[i])
|
|
self.conns[i] = False
|
|
elif True in [c["resolution"].endswith("." + dom) for dom in self.wl_domains]:
|
|
self.whitelist.append(self.conns[i])
|
|
self.conns[i] = False
|
|
elif True in [IPAddress(c["ip_dst"]) in cidr for cidr in self.wl_cidrs]:
|
|
self.whitelist.append(self.conns[i])
|
|
self.conns[i] = False
|
|
|
|
# Let's delete whitelisted connections.
|
|
self.conns = list(filter(lambda c: c != False, self.conns))
|
|
|
|
if self.heuristics_analysis:
|
|
for c in self.conns:
|
|
# Check for UDP / ICMP (strange from a smartphone.)
|
|
if c["proto"] in ["UDP", "ICMP"]:
|
|
c["alert_tiggered"] = True
|
|
self.alerts.append({"title": self.template["PROTO-01"]["title"].format(c["proto"].upper(), c["resolution"]),
|
|
"description": self.template["PROTO-01"]["description"].format(c["proto"].upper(), c["resolution"]),
|
|
"host": c["resolution"],
|
|
"level": "Moderate",
|
|
"id": "PROTO-01"})
|
|
# Check for use of ports over 1024.
|
|
if c["port_dst"] >= max_ports:
|
|
c["alert_tiggered"] = True
|
|
self.alerts.append({"title": self.template["PROTO-02"]["title"].format(c["proto"].upper(), c["resolution"], max_ports),
|
|
"description": self.template["PROTO-02"]["description"].format(c["proto"].upper(), c["resolution"], c["port_dst"]),
|
|
"host": c["resolution"],
|
|
"level": "Low",
|
|
"id": "PROTO-02"})
|
|
# Check for use of HTTP.
|
|
if c["service"] == "http" and c["port_dst"] == http_default_port:
|
|
c["alert_tiggered"] = True
|
|
self.alerts.append({"title": self.template["PROTO-03"]["title"].format(c["resolution"]),
|
|
"description": self.template["PROTO-03"]["description"].format(c["resolution"]),
|
|
"host": c["resolution"],
|
|
"level": "Low",
|
|
"id": "PROTO-03"})
|
|
|
|
# Check for use of HTTP on a non standard port.
|
|
if c["service"] == "http" and c["port_dst"] != http_default_port:
|
|
c["alert_tiggered"] = True
|
|
self.alerts.append({"title": self.template["PROTO-04"]["title"].format(c["resolution"], c["port_dst"]),
|
|
"description": self.template["PROTO-04"]["description"].format(c["resolution"], c["port_dst"]),
|
|
"host": c["resolution"],
|
|
"level": "Moderate",
|
|
"id": "PROTO-04"})
|
|
# Check for non-resolved IP address.
|
|
if c["ip_dst"] == c["resolution"]:
|
|
c["alert_tiggered"] = True
|
|
self.alerts.append({"title": self.template["PROTO-05"]["title"].format(c["ip_dst"]),
|
|
"description": self.template["PROTO-05"]["description"].format(c["ip_dst"]),
|
|
"host": c["ip_dst"],
|
|
"level": "Low",
|
|
"id": "PROTO-05"})
|
|
|
|
if self.iocs_analysis:
|
|
|
|
for c in self.conns:
|
|
# Check for blacklisted IP address.
|
|
for host in self.bl_hosts:
|
|
if c["ip_dst"] == host[0]:
|
|
c["alert_tiggered"] = True
|
|
self.alerts.append({"title": self.template["IOC-01"]["title"].format(c["resolution"], c["ip_dst"], host[1].upper()),
|
|
"description": self.template["IOC-01"]["description"].format(c["ip_dst"]),
|
|
"host": c["resolution"],
|
|
"level": "High",
|
|
"id": "IOC-01"})
|
|
break
|
|
# Check for blacklisted CIDR.
|
|
for cidr in self.bl_cidrs:
|
|
if IPAddress(c["ip_dst"]) in cidr[0]:
|
|
c["alert_tiggered"] = True
|
|
self.alerts.append({"title": self.template["IOC-02"]["title"].format(c["resolution"], cidr[0], cidr[1].upper()),
|
|
"description": self.template["IOC-02"]["description"].format(c["resolution"]),
|
|
"host": c["resolution"],
|
|
"level": "Moderate",
|
|
"id": "IOC-02"})
|
|
# Check for blacklisted domain.
|
|
for domain in self.bl_domains:
|
|
if c["resolution"].endswith(domain[0]):
|
|
if domain[1] != "tracker":
|
|
c["alert_tiggered"] = True
|
|
self.alerts.append({"title": self.template["IOC-03"]["title"].format(c["resolution"], domain[1].upper()),
|
|
"description": self.template["IOC-03"]["description"].format(c["resolution"]),
|
|
"host": c["resolution"],
|
|
"level": "High",
|
|
"id": "IOC-03"})
|
|
else:
|
|
c["alert_tiggered"] = True
|
|
self.alerts.append({"title": self.template["IOC-04"]["title"].format(c["resolution"], domain[1].upper()),
|
|
"description": self.template["IOC-04"]["description"].format(c["resolution"]),
|
|
"host": c["resolution"],
|
|
"level": "Moderate",
|
|
"id": "IOC-04"})
|
|
# Check for blacklisted FreeDNS.
|
|
for domain in self.bl_freedns:
|
|
if c["resolution"].endswith("." + domain[0]):
|
|
c["alert_tiggered"] = True
|
|
self.alerts.append({"title": self.template["IOC-05"]["title"].format(c["resolution"]),
|
|
"description": self.template["IOC-05"]["description"].format(c["resolution"]),
|
|
"host": c["resolution"],
|
|
"level": "Moderate",
|
|
"id": "IOC-05"})
|
|
|
|
# Check for suspect tlds.
|
|
for tld in self.bl_tlds:
|
|
if c["resolution"].endswith(tld[0]):
|
|
c["alert_tiggered"] = True
|
|
self.alerts.append({"title": self.template["IOC-06"]["title"].format(c["resolution"]),
|
|
"description": self.template["IOC-06"]["description"].format(c["resolution"], tld[0]),
|
|
"host": c["resolution"],
|
|
"level": "Low",
|
|
"id": "IOC-06"})
|
|
if self.active_analysis:
|
|
for c in self.conns:
|
|
try: # Domain nameservers check.
|
|
name_servers = pydig.query(c["resolution"], "NS")
|
|
if len(name_servers):
|
|
for ns in self.bl_nameservers:
|
|
if name_servers[0].endswith(".{}.".format(ns[0])):
|
|
c["alert_tiggered"] = True
|
|
self.alerts.append({"title": self.template["ACT-01"]["title"].format(c["resolution"], name_servers[0]),
|
|
"description": self.template["ACT-01"]["description"].format(c["resolution"]),
|
|
"host": c["resolution"],
|
|
"level": "Moderate",
|
|
"id": "ACT-01"})
|
|
except:
|
|
pass
|
|
|
|
try: # Domain history check.
|
|
|
|
whois_record = whois.whois(c["resolution"])
|
|
creation_date = whois_record.creation_date if type(
|
|
whois_record.creation_date) is not list else whois_record.creation_date[0]
|
|
creation_days = abs((datetime.now() - creation_date).days)
|
|
if creation_days < 365:
|
|
c["alert_tiggered"] = True
|
|
self.alerts.append({"title": self.template["ACT-02"]["title"].format(c["resolution"], creation_days),
|
|
"description": self.template["ACT-02"]["description"].format(c["resolution"]),
|
|
"host": c["resolution"],
|
|
"level": "Moderate",
|
|
"id": "ACT-02"})
|
|
|
|
except:
|
|
pass
|
|
|
|
def files_check(self, dir):
|
|
"""
|
|
Check on the files.log:
|
|
* Check certificates sha1
|
|
* [todo] Check possible binary data or APKs?
|
|
:return: nothing - all stuff appended to self.alerts
|
|
"""
|
|
|
|
if not self.iocs_analysis:
|
|
return
|
|
|
|
bl_certs = get_iocs("sha1cert")
|
|
|
|
if os.path.isfile(os.path.join(dir, "files.log")):
|
|
for record in ParseZeekLogs(os.path.join(dir, "files.log"), output_format="json", safe_headers=False):
|
|
if record is not None:
|
|
f = {"filename": record["filename"],
|
|
"ip_src": record["id.orig_h"],
|
|
"ip_dst": record["id.orig_p"],
|
|
"mime_type": record["mime_type"],
|
|
"sha1": record["sha1"]}
|
|
if f not in self.files:
|
|
self.files.append(f)
|
|
|
|
for f in self.files:
|
|
if f["mime_type"] == "application/x-x509-user-cert":
|
|
for cert in bl_certs: # Check for blacklisted certificate.
|
|
if f["sha1"] == cert[0]:
|
|
host = self.resolve(f["ip_src"])
|
|
self.alerts.append({"title": self.template["IOC-07"]["title"].format(cert[1].upper(), host),
|
|
"description": self.template["IOC-07"]["description"].format(f["sha1"], host),
|
|
"host": host,
|
|
"level": "High",
|
|
"id": "IOC-07"})
|
|
|
|
def http_check(self, dir):
|
|
"""
|
|
Check on the http.log:
|
|
* Blacklisted domain/tld from the Host header field.
|
|
Can be used when no DNS query have been done during the session (already cached by the device.)
|
|
:return: nothing - all stuff appended to self.alerts
|
|
"""
|
|
|
|
if os.path.isfile(os.path.join(dir, "http.log")):
|
|
for record in ParseZeekLogs(os.path.join(dir, "http.log"), output_format="json", safe_headers=False):
|
|
if record is not None:
|
|
c = {"host": record['host']}
|
|
if c not in self.http:
|
|
self.http.append(c)
|
|
|
|
if self.iocs_analysis:
|
|
for c in self.http:
|
|
|
|
# If we already know the host form DNS, let's continue.
|
|
if c["host"] in [r["domain"] for r in self.dns]:
|
|
continue
|
|
|
|
# Check for blacklisted domain.
|
|
for h in self.bl_domains:
|
|
if h[1] != "tracker":
|
|
if c["host"].endswith(h[0]):
|
|
self.alerts.append({"title": self.template["IOC-08"]["title"].format(c["host"], h[1].upper()),
|
|
"description": self.template["IOC-08"]["description"].format(c["host"]),
|
|
"host": c["host"],
|
|
"level": "High",
|
|
"id": "IOC-08"})
|
|
# Check for freedns.
|
|
for h in self.bl_freedns:
|
|
if c["host"].endswith(h[0]):
|
|
self.alerts.append({"title": self.template["IOC-09"]["title"].format(c["host"]),
|
|
"description": self.template["IOC-09"]["description"].format(c["host"]),
|
|
"host": c["host"],
|
|
"level": "Moderate",
|
|
"id": "IOC-09"})
|
|
# Check for fancy TLD.
|
|
for h in self.bl_tlds:
|
|
if c["host"].endswith(h[0]):
|
|
self.alerts.append({"title": self.template["IOC-10"]["title"].format(c["host"]),
|
|
"description": self.template["IOC-10"]["description"].format(c["host"], h[0]),
|
|
"host": c["host"],
|
|
"level": "Low",
|
|
"id": "IOC-10"})
|
|
|
|
def ssl_check(self, dir):
|
|
"""
|
|
Check on the ssl.log:
|
|
* SSL connections which doesn't use the 443.
|
|
* "Free" certificate issuer (taken from the config).
|
|
* Self-signed certificates.
|
|
* Blacklisted domain in the CN
|
|
:return: nothing - all stuff appended to self.alerts
|
|
"""
|
|
ssl_default_ports = get_config(("analysis", "ssl_default_ports"))
|
|
free_issuers = get_config(("analysis", "free_issuers"))
|
|
|
|
if os.path.isfile(os.path.join(dir, "ssl.log")):
|
|
for record in ParseZeekLogs(os.path.join(dir, "ssl.log"), output_format="json", safe_headers=False):
|
|
if record is not None:
|
|
c = {"host": record['id.resp_h'],
|
|
"port": record['id.resp_p'],
|
|
"issuer": record["issuer"] if "issuer" in record else "",
|
|
"validation_status": record["validation_status"],
|
|
"cn": record["server_name"] if "server_name" in record else ""}
|
|
if c not in self.ssl:
|
|
self.ssl.append(c)
|
|
|
|
if self.heuristics_analysis:
|
|
for cert in self.ssl:
|
|
host = self.resolve(cert["host"])
|
|
|
|
# If the associated host has not whitelisted, check the cert.
|
|
for c in self.conns:
|
|
if host in c["resolution"]:
|
|
# Check for non generic SSL port.
|
|
if cert["port"] not in ssl_default_ports:
|
|
c["alert_tiggered"] = True
|
|
self.alerts.append({"title": self.template["SSL-01"]["title"].format(cert["port"], host),
|
|
"description": self.template["SSL-01"]["description"].format(host),
|
|
"host": host,
|
|
"level": "Moderate",
|
|
"id": "SSL-01"})
|
|
# Check Free SSL certificates.
|
|
if cert["issuer"] in free_issuers:
|
|
c["alert_tiggered"] = True
|
|
self.alerts.append({"title": self.template["SSL-02"]["title"].format(host),
|
|
"description": self.template["SSL-02"]["description"],
|
|
"host": host,
|
|
"level": "Moderate",
|
|
"id": "SSL-02"})
|
|
# Check for self-signed certificates.
|
|
if cert["validation_status"] == "self signed certificate in certificate chain":
|
|
c["alert_tiggered"] = True
|
|
self.alerts.append({"title": self.template["SSL-03"]["title"].format(host),
|
|
"description": self.template["SSL-03"]["description"].format(host),
|
|
"host": host,
|
|
"level": "Moderate",
|
|
"id": "SSL-03"})
|
|
|
|
if self.iocs_analysis:
|
|
for cert in self.ssl:
|
|
# Check if the domain in the certificate haven't been blacklisted
|
|
# This check can be good if the domain has already been cached by
|
|
# the device so it wont appear in self.dns.
|
|
|
|
if any([cert["cn"].endswith(r["domain"]) for r in self.dns]):
|
|
continue
|
|
|
|
for domain in self.bl_domains:
|
|
if domain[1] != "tracker":
|
|
if cert["cn"].endswith(domain[0]):
|
|
self.alerts.append({"title": self.template["SSL-04"]["title"].format(domain[0], domain[1].upper()),
|
|
"description": self.template["SSL-04"]["description"].format(domain[0]),
|
|
"host": domain[0],
|
|
"level": "High",
|
|
"id": "SSL-04"})
|
|
|
|
def alerts_check(self):
|
|
"""
|
|
Leverage an advice to the user based on the trigered hosts
|
|
:return: nothing - all generated alerts appended to self.alerts
|
|
"""
|
|
hosts = {}
|
|
|
|
for alert in [dict(t) for t in {tuple(d.items()) for d in self.alerts}]:
|
|
if alert["host"] not in hosts:
|
|
hosts[alert["host"]] = 1
|
|
else:
|
|
hosts[alert["host"]] += 1
|
|
|
|
for host, nb in hosts.items():
|
|
if nb >= get_config(("analysis", "max_alerts")):
|
|
self.alerts.append({"title": self.template["ADV-01"]["title"].format(host),
|
|
"description": self.template["ADV-01"]["description"].format(host, nb),
|
|
"host": host,
|
|
"level": "Moderate",
|
|
"id": "ADV-01"})
|
|
|
|
def resolve(self, ip_addr):
|
|
"""
|
|
A simple method to retreive DNS names from IP addresses
|
|
in order to replace them in alerts.
|
|
|
|
:return: String - DNS record or IP Address.
|
|
"""
|
|
for record in self.dns:
|
|
if ip_addr in record["answers"]:
|
|
return record["domain"]
|
|
return ip_addr
|
|
|
|
def start_zeek(self):
|
|
"""
|
|
Start zeek and check the logs.
|
|
"""
|
|
sp.Popen("cd {} && /opt/zeek/bin/zeek -Cr capture.pcap protocols/ssl/validate-certs".format(
|
|
self.working_dir), shell=True).wait()
|
|
sp.Popen("cd {} && mv *.log assets/".format(self.working_dir),
|
|
shell=True).wait()
|
|
self.fill_dns(self.working_dir + "/assets/")
|
|
self.netflow_check(self.working_dir + "/assets/")
|
|
self.ssl_check(self.working_dir + "/assets/")
|
|
self.http_check(self.working_dir + "/assets/")
|
|
self.files_check(self.working_dir + "/assets/")
|
|
self.alerts_check()
|
|
|
|
def retrieve_alerts(self):
|
|
"""
|
|
Retrieve alerts.
|
|
:return: list - a list of alerts wihout duplicates.
|
|
"""
|
|
return [dict(t) for t in {tuple(d.items()) for d in self.alerts}]
|
|
|
|
def retrieve_whitelist(self):
|
|
"""
|
|
Retrieve whitelisted elements.
|
|
:return: list - a list of whitelisted elements wihout duplicates.
|
|
"""
|
|
return [dict(t) for t in {tuple(d.items()) for d in self.whitelist}]
|
|
|
|
def retrieve_conns(self):
|
|
"""
|
|
Retrieve not whitelisted elements.
|
|
:return: list - a list of non-whitelisted elements wihout duplicates.
|
|
"""
|
|
return self.conns
|