Initial commit

tools/generate-cisco-umbrella-blockpage.py

@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+
+import ipaddress
+import logging
+from typing import List, Tuple
+
+from generator import get_version, write_to_file, Dns, create_resolver
+
+# Static Umbrella blockpage addresses: https://docs.umbrella.com/deployment-umbrella/docs/block-page-ip-addresses
+blockpage_ip_list = ['146.112.61.104', '::ffff:146.112.61.104', '146.112.61.105', '::ffff:146.112.61.105', '146.112.61.106', '::ffff:146.112.61.106', '146.112.61.107', '::ffff:146.112.61.107', '146.112.61.108', '::ffff:146.112.61.108', '146.112.61.110', '::ffff:146.112.61.110']
+
+
+def process(ipv4: List, ipv6: List, hostname: List):
+    # Cisco Umbrella blockpage Domains
+    umbrella_blockpage_hostname_dst = 'umbrella-blockpage-hostname'
+    umbrella_blockpage_warninglist = {
+        'description': 'Event contains one or more Cisco Umbrella blockpage hostnames as attribute with an IDS flag set',
+        'name': 'List of known Cisco Umbrella blockpage hostnames',
+        'type': 'hostname',
+        'matching_attributes': ['hostname', 'domain', 'url', 'domain|ip']
+    }
+    generate(hostname, umbrella_blockpage_warninglist, umbrella_blockpage_hostname_dst)
+
+    # Cisco Umbrella blockpage IPv4
+    umbrella_blockpage_ipv4_dst = 'umbrella-blockpage-v4'
+    umbrella_blockpage_ipv4_warninglist = {
+        'description': 'Event contains one or more public IPv4 DNS resolvers as attribute with an IDS flag set',
+        'name': 'List of known IPv4 public DNS resolvers',
+        'type': 'cidr',
+        'matching_attributes': ['ip-src', 'ip-dst', 'domain|ip']
+    }
+    generate(ipv4, umbrella_blockpage_ipv4_warninglist, umbrella_blockpage_ipv4_dst)
+
+    # Cisco Umbrella blockpage IPv6
+    umbrella_blockpage_ipv6_dst = 'umbrella-blockpage-v6'
+    umbrella_blockpage_ipv6_warninglist = {
+        'description': 'Event contains one or more public IPv6 DNS resolvers as attribute with an IDS flag set',
+        'name': 'List of known IPv6 public DNS resolvers',
+        'type': 'cidr',
+        'matching_attributes': ['ip-src', 'ip-dst', 'domain|ip']
+    }
+    generate(ipv6, umbrella_blockpage_ipv6_warninglist, umbrella_blockpage_ipv6_dst)
+
+
+def generate(data_list, warninglist, dst):
+    warninglist['version'] = get_version()
+    warninglist['list'] = data_list
+
+    write_to_file(warninglist, dst)
+
+
+def main():
+    dns = Dns(create_resolver())
+
+    ipv4_addresses = []
+    ipv6_addresses = []
+    host_names = []
+    
+    for ip in blockpage_ip_list:
+        host_names.append(dns.get_domain_from_ip(ip))
+
+        try:
+            ip = ipaddress.ip_address(ip)
+
+            if ip.version == 4:
+                ipv4_addresses.append(ip.compressed)
+            elif ip.version == 6:
+                ipv6_addresses.append(ip.compressed)
+
+        except ValueError as exc:
+            logging.warning(str(exc))
+        
+    process(ipv4_addresses, ipv6_addresses, host_names)
+
+if __name__ == '__main__':
+    main()

tools/generator.py

@@ -10,6 +10,7 @@ import gzip
 import requests
 import dns.exception
 import dns.resolver
+import dns.reversename
 from dateutil.parser import parse as parsedate
 
 
@@ -247,6 +248,15 @@ class Dns:
 
         return ranges
 
+    def get_domain_from_ip(self, ip: str) -> str:
+        try:
+            records = dns.reversename.from_address(ip)
+        except (dns.resolver.NoAnswer, dns.resolver.NXDOMAIN, dns.exception.Timeout, dns.resolver.NoNameservers) as e:
+            logging.info("Could not fetch PTR record for IP {}: {}".format(ip, str(e)))
+            return []          
+
+        return str(dns.resolver.resolve(records,"PTR")[0]).rstrip('.')
+
 
 def main():
     init_logging()