misp-modules/misp_modules/modules/expansion/crowdsec.py

import ipaddress
import json

import pycountry
import requests
from pymisp import MISPEvent, MISPObject

from . import check_input_attribute, standard_error_message

mispattributes = {"input": ["ip-dst", "ip-src"], "format": "misp_standard"}
moduleinfo = {
    "version": "2.1",
    "author": "Shivam Sandbhor <shivam@crowdsec.net>",
    "description": "Module to access CrowdSec CTI API.",
    "module-type": ["hover", "expansion"],
    "name": "CrowdSec CTI",
    "logo": "crowdsec.png",
    "requirements": [
        "A CrowdSec CTI API key. Get yours by following https://docs.crowdsec.net/docs/cti_api/getting_started/#getting-an-api-key"
    ],
    "features": "This module enables IP lookup from CrowdSec CTI API. It provides information about the IP, such as what kind of attacks it has been participant of as seen by CrowdSec's network. It also includes enrichment by CrowdSec like background noise score, aggressivity over time etc.",
    "references": [
        "https://www.crowdsec.net/",
        "https://docs.crowdsec.net/docs/cti_api/getting_started",
        "https://app.crowdsec.net/",
    ],
    "input": "An IP address.",
    "output": "IP Lookup information from CrowdSec CTI API",
}
moduleconfig = [
    "api_key",
    "add_reputation_tag",
    "add_behavior_tag",
    "add_classification_tag",
    "add_mitre_technique_tag",
    "add_cve_tag",
]


def handler(q=False):
    if q is False:
        return False

    request = json.loads(q)
    if not request.get("config"):
        return {"error": "Missing CrowdSec Config"}

    if not request["config"].get("api_key"):
        return {"error": "Missing CrowdSec API key"}

    if not request.get("attribute") or not check_input_attribute(request["attribute"]):
        return {
            "error": f"{standard_error_message}, which should contain at least a type, a value and an uuid."
        }

    if request["attribute"].get("type") not in mispattributes["input"]:
        return {
            "error": f"Wrong input type. Please choose on of the following: {', '.join(mispattributes['input'])}"
        }

    return _handler_v2(request)


def _get_boolean_config(request_data, config: str, default_config: bool):
    if request_data["config"].get(config) is None:
        return default_config
    raw_config = request_data["config"].get(config).lower()
    # falsy values, return False
    if raw_config in ["false", "0", "no", "off"]:
        return False
    # truthy values, return True
    if raw_config in ["true", "1", "yes", "on"]:
        return True
    return default_config


def _handler_v2(request_data):
    attribute = request_data["attribute"]
    ip = attribute["value"]
    # Validate IP
    try:
        ipaddress.ip_address(ip)
    except ValueError:
        return {
            "error": f"IP ({ip}) is not valid for calling CrowdSec CTI. Please provide a valid IP address."
        }

    crowdsec_cti = requests.get(
        f"https://cti.api.crowdsec.net/v2/smoke/{ip}",
        headers={
            "x-api-key": request_data["config"]["api_key"],
            "User-Agent": "crowdsec-misp/v2.1.1",
        },
    )
    crowdsec_cti.raise_for_status()
    crowdsec_cti = crowdsec_cti.json()

    add_reputation_tag = _get_boolean_config(request_data, "add_reputation_tag", True)
    add_behavior_tag = _get_boolean_config(request_data, "add_behavior_tag", True)
    add_classification_tag = _get_boolean_config(
        request_data, "add_classification_tag", True
    )
    add_mitre_technique_tag = _get_boolean_config(
        request_data, "add_mitre_technique_tag", True
    )
    add_cve_tag = _get_boolean_config(request_data, "add_cve_tag", True)

    misp_event = MISPEvent()
    misp_attribute = misp_event.add_attribute(**attribute)
    crowdsec_context_object = MISPObject("crowdsec-ip-context")
    crowdsec_context_object.from_dict(
        first_seen=crowdsec_cti["history"]["first_seen"],
        last_seen=crowdsec_cti["history"]["last_seen"],
    )
    ip_attribute = crowdsec_context_object.add_attribute("ip", crowdsec_cti["ip"])
    reputation = crowdsec_cti["reputation"] or "unknown"
    crowdsec_context_object.add_attribute("reputation", reputation)
    if add_reputation_tag:
        tag = f'crowdsec:reputation="{reputation}"'
        ip_attribute.add_tag(tag)
    crowdsec_context_object.add_attribute("ip-range", crowdsec_cti["ip_range"])
    crowdsec_context_object.add_attribute(
        "ip-range-score", crowdsec_cti["ip_range_score"]
    )
    crowdsec_context_object.add_attribute(
        "country", get_country_name_from_alpha_2(crowdsec_cti["location"]["country"])
    )
    crowdsec_context_object.add_attribute(
        "country-code", crowdsec_cti["location"]["country"]
    )
    if crowdsec_cti["location"].get("city"):
        crowdsec_context_object.add_attribute("city", crowdsec_cti["location"]["city"])
    crowdsec_context_object.add_attribute(
        "latitude", crowdsec_cti["location"]["latitude"]
    )
    crowdsec_context_object.add_attribute(
        "longitude", crowdsec_cti["location"]["longitude"]
    )
    crowdsec_context_object.add_attribute("as-name", crowdsec_cti["as_name"])
    crowdsec_context_object.add_attribute("as-num", crowdsec_cti["as_num"])
    if crowdsec_cti.get("reverse_dns") is not None:
        crowdsec_context_object.add_attribute(
            "reverse-dns", crowdsec_cti["reverse_dns"]
        )
    crowdsec_context_object.add_attribute(
        "background-noise", crowdsec_cti["background_noise_score"]
    )
    for behavior in crowdsec_cti["behaviors"]:
        crowdsec_context_object.add_attribute(
            "behaviors", behavior["label"], comment=behavior["description"]
        )
        if add_behavior_tag:
            tag = f'crowdsec:behavior="{behavior["name"]}"'
            ip_attribute.add_tag(tag)
    for technique in crowdsec_cti["mitre_techniques"]:
        technique_name = technique["name"]
        mitre_url = (
            f"https://attack.mitre.org/tactics/{technique_name}"
            if technique_name.startswith("TA")
            else f"https://attack.mitre.org/techniques/{technique_name}"
        )
        crowdsec_context_object.add_attribute(
            "mitre-techniques",
            technique["label"],
            comment=f'{technique["description"]} ({mitre_url})',
        )
        if add_mitre_technique_tag:
            tag = f'crowdsec:mitre-technique="{technique_name}"'
            ip_attribute.add_tag(tag)

    for cve in crowdsec_cti["cves"]:
        cve_url = f"https://nvd.nist.gov/vuln/detail/{cve}"
        crowdsec_context_object.add_attribute("cves", cve, comment=cve_url)
        if add_cve_tag:
            tag = f'crowdsec:cve="{cve}"'
            ip_attribute.add_tag(tag)

    for feature, values in crowdsec_cti["classifications"].items():
        field = feature[:-1]
        for value in values:
            crowdsec_context_object.add_attribute(
                feature, value["label"], comment=value["description"]
            )
            if add_classification_tag:
                tag = f'crowdsec:{field}="{value["name"]}"'
                ip_attribute.add_tag(tag)
    crowdsec_context_object.add_attribute(
        "attack-details",
        ", ".join(
            f"{scenario['name']} - {scenario['label']} ({scenario['description']})"
            for scenario in crowdsec_cti["attack_details"]
        ),
    )
    crowdsec_context_object.add_attribute(
        "target-countries",
        ", ".join(
            map(get_country_name_from_alpha_2, crowdsec_cti["target_countries"].keys())
        ),
    )
    crowdsec_context_object.add_attribute(
        "trust", crowdsec_cti["scores"]["overall"]["trust"]
    )
    scores = []
    for time_period, indicators in crowdsec_cti["scores"].items():
        tp = " ".join(map(str.capitalize, time_period.split("_")))
        indicator = (
            f"{indicator_type.capitalize()}: {indicator_value}"
            for indicator_type, indicator_value in indicators.items()
        )
        scores.append(f"{tp}: {' - '.join(indicator)}")
    crowdsec_context_object.add_attribute("scores", ", ".join(scores))
    crowdsec_context_object.add_reference(misp_attribute.uuid, "related-to")
    misp_event.add_object(crowdsec_context_object)

    event = json.loads(misp_event.to_json())
    results = {
        key: event[key]
        for key in ("Attribute", "Object")
        if (key in event and event[key])
    }
    return {"results": results}


def get_country_name_from_alpha_2(alpha_2):
    country_info = pycountry.countries.get(alpha_2=alpha_2)
    return country_info.name if country_info else None


def introspection():
    return mispattributes


def version():
    moduleinfo["config"] = moduleconfig
    return moduleinfo