CrowdStrike Falcon Threat Intelligence

The CrowdStrike Falcon Indicators integration uses a local database so it only has to download new and updated indicators at each interval.

There are several configurable options for CrowdStrike indicators. In addition to selecting which indicator types to collect, you can also set how many days worth of indicators to use, based on published_days, and the number of days to keep indicators in the local DB (database_retention). Confidence level filters and do notice settings are also available for each indicator type.

Intel Malicious confidence options are: “high”, “medium”, “low”, or “unverified”. The following definitions apply to malicious_confidence:

  • high: If indicator is an IP or domain, it has been associated with malicious activity within the last 60 days.

  • medium: If indicator is an IP or domain, it has been associated with malicious activity within the last 60-120 days.

  • low: If indicator is an IP or domain, it has been associated with malicious activity exceeding 120 days.

  • unverified: This indicator has not been verified by a CrowdStrike Intelligence analyst or an automated system.

Once downloaded and processed, the data will be merged with all other intel files (if there are any), and published. If “intel” in enabled in the “push_content” settings, the file will automatically get pushed to the Fleet Manager policy and/or all sensors in the policy. See Push content settings for more details.

Attention

Downloading intel indicators from CrowdStrike requires a Falcon Intelligence subscription or better. The Client ID and Client Secret need access to the following API: https://api.crowdstrike.com/intel/combined/indicators/v1

Settings

crowdstrike_indicators:
  id:                                   # Falcon API Client ID
  secret:                               # Falcon API Secret
  encrypted_secret:                     # Encrypted Falcon API Secret (use either secret or encrypted_secret)
  member_cid:                           # Falcon API Member_CID (multi-tenant only)
  cloud: us-1                           # Falcon Cloud (us-1, us-2, eu-1, us-gov-1, us-gov-2)
  host_override:                        # Optional: Override the default host for the Falcon API
  base_path_override:                   # Optional: Override the default base path for the Falcon API
  debug: false                          # Debug logging will expose the Client ID and Secret in the logs
  enabled: false
  interval_hours: 0
  request_limit: 10000                  # This setting should only be changed if directed by support
  published_days: 30                    # How many days worth of indicators to use in the Intel file
  database_retention: 90                # How many days to keep indicators in the local DB

  type_ip_address: true
  type_ip_address_do_notice: true
  type_ip_address_confidence: high

  type_ip_address_block: true
  type_ip_address_block_do_notice: true
  type_ip_address_block_confidence: high

  type_url: true                       # Includes http, https and TCP URLs
  type_https_url: false                # This should only be enabled if TLS decryption is in use
  type_url_do_notice: true
  type_url_confidence: high

  type_email_address: true
  type_email_address_do_notice: true
  type_email_address_confidence: high

  type_domain: true
  type_domain_do_notice: true
  type_domain_confidence: high

  type_x509_subject: true
  type_x509_subject_do_notice: true
  type_x509_subject_confidence: high

  type_username: true
  type_username_do_notice: true
  type_username_confidence: high

  type_hash_md5: true                # There is no confidence level filter for hash indicators, they are always considered high confidence
  type_hash_md5_do_notice: true

  type_hash_sha256: true             # There is no confidence level filter for hash indicators, they are always considered high confidence
  type_hash_sha256_do_notice: true

  type_file_name: true
  type_file_name_do_notice: true
  type_file_name_confidence: high

  targets:
  threat_types:

In addition to configuring which indicators to collect, you can also filter the indicators based on the type of target or the threat type.

  • To list a single Target or Threat Type, enter the string with both double quotes and single quotes.

  • To list multiple Targets or Threat Types, enter the string with both double quotes and square brackets around the entire string, and single quotes around each item.

Examples:

targets:         "'Aerospace'"
threat_types:    "['Commodity','Ransomware']"

The following is a sample input file created by this integration, using tab-separated values.

#fields      indicator indicator_type  meta.source  meta.desc                              meta.url                          meta.do_notice  meta.confidence   meta.threat_score  meta.risk_score  meta.verdict      meta.verdict_source  meta.firstseen  meta.lastseen      meta.associated  meta.category  meta.campaigns  meta.kill_chain                     meta.reports
141.10.232.21            Intel::ADDR     CrowdStrike CrowdStrike Threat Intelligence   https://api.us-2.crowdstrike.com      T                     high                  -                    -                    -             -                      -                 -              -                  -                    -                 C2                                        -
41.65.243.190            Intel::ADDR     CrowdStrike CrowdStrike Threat Intelligence   https://api.us-2.crowdstrike.com      T                     high                  -                    -                    -             -                      -                 -              -                  -                    -                 C2                                        -
12.22.202.26     Intel::ADDR     CrowdStrike CrowdStrike Threat Intelligence   https://api.us-2.crowdstrike.com      T                     high                  -                    -                    -             -                      -                 -              -                  -                    -                 Installation,C2,ActionOnObjectives        -

Intel log

This integration will enrich the intel.log with content like the following:

 {
   "@path":"intel",
   "@sensor":"Lab-AP200",
   "@timestamp":"2023-01-06T05:13:38.841292Z",
   "ts":"2023-01-06T05:13:38.841292Z",
   "uid":"CNh51N3dSRfMZG1Pt4",
   "id.orig_h":"195.133.40.86",
   "id.orig_p":64910,
   "id.resp_h":"192.168.13.20",
   "id.resp_p":80,
   "seen.indicator":"77.247.181.165",
   "seen.indicator_type":"Intel::ADDR",
   "seen.where":"Conn::IN_ORIG",
   "matched": [
     "Intel::ADDR"
   ],
   "sources": [
     "blocklist_de",
     "cinsscore_ci_badguys",
     "blocklist_net_ua",
     "Mandiant",
     "dshield_block"
   ],
 }

If the ExtendIntel Zeek package is loaded, the intel.log will be enriched with additional content like the following: (all indicators will not have all fields)

  {
    "confidence": [99],
    "threat_score": [100],
    "verdict": ["malicious"],
    "verdict_source": ["analystVerdict"],
    "desc": ["Mandiant Threat Intellegence"]
    "lastseen": ["2023-01-03T16:10:54Z"],
    "firstseen": ["2021-03-20T10:10:01Z"],
    "url": ["https://advantage.mandiant.com/"],
    "reports": ["ID:23-00000242, Type:News Analysis"],
    "campaigns": [],
    "associated": [
      "ID:threat-actor--b7e371c2-724e-5ffa-9e3c-9b1410513c27, Name:FIN13; ID:threat-actor--8211bc17-9216-5e83-b54d-d1b04add12f3, Name:APT28; ID:threat-actor--7a39953e-0dae-569a-9d49-d52a4a8865b1, Name:APT29; ID:threat-actor--2f0ab36a-02a6-59f7-ac23-bcd824cc7c8e, Name:FIN4"
    ],
    "category": [
      "exploit",
      "exploit/vuln-scanning, exploit"
    ],
  }