#!/var/ossec/framework/python/bin/python3 ## MISP API Integration # import sys import os from socket import socket, AF_UNIX, SOCK_DGRAM from datetime import date, datetime, timedelta import time import requests from requests.exceptions import ConnectionError import json import ipaddress import hashlib import re pwd = os.path.dirname(os.path.dirname(os.path.realpath(__file__))) socket_addr = "{0}/queue/sockets/queue".format(pwd) def send_event(msg, agent=None): if not agent or agent["id"] == "000": string = "1:misp:{0}".format(json.dumps(msg)) else: string = "1:[{0}] ({1}) {2}->misp:{3}".format( agent["id"], agent["name"], agent["ip"] if "ip" in agent else "any", json.dumps(msg), ) sock = socket(AF_UNIX, SOCK_DGRAM) sock.connect(socket_addr) sock.send(string.encode()) sock.close() false = False # Read configuration parameters alert_file = open(sys.argv[1]) # Read the alert file alert = json.loads(alert_file.read()) alert_file.close() # New Alert Output if MISP Alert or Error calling the API alert_output = {} # MISP Server Base URL misp_base_url = "https://**your misp instance**/attributes/restSearch/" # MISP Server API AUTH KEY misp_api_auth_key = "*Your API Key" # API - HTTP Headers misp_apicall_headers = { "Content-Type": "application/json", "Authorization": f"{misp_api_auth_key}", "Accept": "application/json", } ## Extract Sysmon for Windows/Sysmon for Linux and Sysmon Event ID event_source = alert["rule"]["groups"][0] event_type = alert["rule"]["groups"][2] ## Regex Pattern used based on SHA256 lenght (64 characters) regex_file_hash = re.compile("\w{64}") if event_source == "windows": if event_type == "sysmon_event1": try: wazuh_event_param = regex_file_hash.search( alert["data"]["win"]["eventdata"]["hashes"] ).group(0) except IndexError: sys.exit() elif ( event_type == "sysmon_event3" and alert["data"]["win"]["eventdata"]["destinationIsIpv6"] == "false" ): try: dst_ip = alert["data"]["win"]["eventdata"]["destinationIp"] if ipaddress.ip_address(dst_ip).is_global: wazuh_event_param = dst_ip else: sys.exit() except IndexError: sys.exit() elif ( event_type == "sysmon_event3" and alert_output["data"]["win"]["eventdata"]["destinationIsIpv6"] == "true" ): sys.exit() elif event_type == "sysmon_event6": try: wazuh_event_param = regex_file_hash.search( alert["data"]["win"]["eventdata"]["hashes"] ).group(0) except IndexError: sys.exit() elif event_type == "sysmon_event7": try: wazuh_event_param = regex_file_hash.search( alert["data"]["win"]["eventdata"]["hashes"] ).group(0) except IndexError: sys.exit() elif event_type == "sysmon_event_15": try: wazuh_event_param = regex_file_hash.search( alert["data"]["win"]["eventdata"]["hashes"] ).group(0) except IndexError: sys.exit() elif event_type == "sysmon_event_22": try: wazuh_event_param = alert["data"]["win"]["eventdata"]["queryName"] except IndexError: sys.exit() elif event_type == "sysmon_event_23": try: wazuh_event_param = regex_file_hash.search( alert["data"]["win"]["eventdata"]["hashes"] ).group(0) except IndexError: sys.exit() elif event_type == "sysmon_event_24": try: wazuh_event_param = regex_file_hash.search( alert["data"]["win"]["eventdata"]["hashes"] ).group(0) except IndexError: sys.exit() elif event_type == "sysmon_event_25": try: wazuh_event_param = regex_file_hash.search( alert["data"]["win"]["eventdata"]["hashes"] ).group(0) except IndexError: sys.exit() else: sys.exit() misp_search_value = "value:" f"{wazuh_event_param}" misp_search_url = "".join([misp_base_url, misp_search_value]) try: misp_api_response = requests.get( misp_search_url, headers=misp_apicall_headers, verify=False ) except ConnectionError: alert_output["misp"] = {} alert_output["integration"] = "misp" alert_output["misp"]["error"] = "Connection Error to MISP API" send_event(alert_output, alert["agent"]) else: misp_api_response = misp_api_response.json() # Check if response includes Attributes (IoCs) if misp_api_response["response"]["Attribute"]: # Generate Alert Output from MISP Response alert_output["misp"] = {} alert_output["integration"] = "misp" alert_output["misp"]["source"] = {} alert_output["misp"]["event_id"] = misp_api_response["response"][ "Attribute" ][0]["event_id"] alert_output["misp"]["category"] = misp_api_response["response"][ "Attribute" ][0]["category"] alert_output["misp"]["value"] = misp_api_response["response"]["Attribute"][ 0 ]["value"] alert_output["misp"]["type"] = misp_api_response["response"]["Attribute"][ 0 ]["type"] alert_output["misp"]["source"]["description"] = alert["rule"]["description"] send_event(alert_output, alert["agent"]) elif event_source == "linux": if ( event_type == "sysmon_event3" and alert["data"]["eventdata"]["destinationIsIpv6"] == "false" ): try: dst_ip = alert["data"]["eventdata"]["DestinationIp"] if ipaddress.ip_address(dst_ip).is_global: wazuh_event_param = dst_ip misp_search_value = "value:" f"{wazuh_event_param}" misp_search_url = "".join([misp_base_url, misp_search_value]) try: misp_api_response = requests.get( misp_search_url, headers=misp_apicall_headers, verify=False ) except ConnectionError: alert_output["misp"] = {} alert_output["integration"] = "misp" alert_output["misp"]["error"] = "Connection Error to MISP API" send_event(alert_output, alert["agent"]) else: misp_api_response = misp_api_response.json() # Check if response includes Attributes (IoCs) if misp_api_response["response"]["Attribute"]: # Generate Alert Output from MISP Response alert_output["misp"] = {} alert_output["integration"] = "misp" alert_output["misp"]["event_id"] = misp_api_response[ "response" ]["Attribute"][0]["event_id"] alert_output["misp"]["category"] = misp_api_response[ "response" ]["Attribute"][0]["category"] alert_output["misp"]["value"] = misp_api_response["response"][ "Attribute" ][0]["value"] alert_output["misp"]["type"] = misp_api_response["response"][ "Attribute" ][0]["type"] send_event(alert_output, alert["agent"]) else: sys.exit() except IndexError: sys.exit() else: sys.exit() elif event_source == "ossec" and event_type == "syscheck_entry_added": try: wazuh_event_param = alert["syscheck"]["sha256_after"] except IndexError: sys.exit() misp_search_value = "value:" f"{wazuh_event_param}" misp_search_url = "".join([misp_base_url, misp_search_value]) try: misp_api_response = requests.get( misp_search_url, headers=misp_apicall_headers, verify=false ) except ConnectionError: alert_output["misp"] = {} alert_output["integration"] = "misp" alert_output["misp"]["error"] = "Connection Error to MISP API" send_event(alert_output, alert["agent"]) else: misp_api_response = misp_api_response.json() # Check if response includes Attributes (IoCs) if misp_api_response["response"]["Attribute"]: # Generate Alert Output from MISP Response alert_output["misp"] = {} alert_output["integration"] = "misp" alert_output["misp"]["event_id"] = misp_api_response["response"][ "Attribute" ][0]["event_id"] alert_output["misp"]["category"] = misp_api_response["response"][ "Attribute" ][0]["category"] alert_output["misp"]["value"] = misp_api_response["response"]["Attribute"][ 0 ]["value"] alert_output["misp"]["type"] = misp_api_response["response"]["Attribute"][ 0 ]["type"] send_event(alert_output, alert["agent"]) else: sys.exit()