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DNS logs

Overview

Cloudflare is a global network designed to make everything you connect to the Internet secure, private, fast, and reliable.

In this documentation, you will learn how to collect and send Cloudflare DNS logs to Sekoia.io.

The following Sekoia.io built-in rules match the intake Cloudflare DNS logs. This documentation is updated automatically and is based solely on the fields used by the intake which are checked against our rules. This means that some rules will be listed but might not be relevant with the intake.

SEKOIA.IO x Cloudflare DNS logs on ATT&CK Navigator

SEKOIA.IO Intelligence Feed

Detect threats based on indicators of compromise (IOCs) collected by SEKOIA's Threat and Detection Research team.

  • Effort: elementary
Sliver DNS Beaconing

Detects suspicious DNS queries known from Sliver beaconing

  • Effort: intermediate

Event Categories

The following table lists the data source offered by this integration.

Data Source Description
DNS records Cloudflare DNS logs provides detailed logs on handled DNS queries

In details, the following table denotes the type of events produced by this integration.

Name Values
Kind event
Category network
Type info

Event Samples

Find below few samples of events and how they are normalized by Sekoia.io.

{
    "message": "{\"QueryName\":\"foO-BAR-baz.xYz.\",\"QueryType\":1,\"ResponseCode\":0,\"Timestamp\":1657233726004000000}\n",
    "event": {
        "category": [
            "network"
        ],
        "dataset": "dns_logs",
        "kind": "event",
        "type": [
            "info"
        ]
    },
    "@timestamp": "2022-07-07T22:42:06.004000Z",
    "dns": {
        "question": {
            "name": "foO-BAR-baz.xYz",
            "registered_domain": "foO-BAR-baz.xYz",
            "top_level_domain": "xYz",
            "type": "A"
        },
        "response_code": "NoError"
    },
    "observer": {
        "type": "dns",
        "vendor": "Cloudflare"
    },
    "related": {
        "hosts": [
            "foO-BAR-baz.xYz"
        ]
    }
}
{
    "message": "{\"QueryName\":\"foO-BAR-baz.xYz.\",\"QueryType\":2,\"ResponseCode\":0,\"Timestamp\":1657233726004000000}\n",
    "event": {
        "category": [
            "network"
        ],
        "dataset": "dns_logs",
        "kind": "event",
        "type": [
            "info"
        ]
    },
    "@timestamp": "2022-07-07T22:42:06.004000Z",
    "dns": {
        "question": {
            "name": "foO-BAR-baz.xYz",
            "registered_domain": "foO-BAR-baz.xYz",
            "top_level_domain": "xYz",
            "type": "NS"
        },
        "response_code": "NoError"
    },
    "observer": {
        "type": "dns",
        "vendor": "Cloudflare"
    },
    "related": {
        "hosts": [
            "foO-BAR-baz.xYz"
        ]
    }
}
{
    "message": "{\"QueryName\":\"foO-BAR-baz.xYz.\",\"QueryType\":28,\"ResponseCode\":0,\"Timestamp\":1657233726004000000}\n",
    "event": {
        "category": [
            "network"
        ],
        "dataset": "dns_logs",
        "kind": "event",
        "type": [
            "info"
        ]
    },
    "@timestamp": "2022-07-07T22:42:06.004000Z",
    "dns": {
        "question": {
            "name": "foO-BAR-baz.xYz",
            "registered_domain": "foO-BAR-baz.xYz",
            "top_level_domain": "xYz",
            "type": "AAAA"
        },
        "response_code": "NoError"
    },
    "observer": {
        "type": "dns",
        "vendor": "Cloudflare"
    },
    "related": {
        "hosts": [
            "foO-BAR-baz.xYz"
        ]
    }
}
{
    "message": "{\"QueryName\":\"foO-BAR-baz.xYz.\",\"QueryType\":65353,\"ResponseCode\":0,\"Timestamp\":1657233726004000000}\n",
    "event": {
        "category": [
            "network"
        ],
        "dataset": "dns_logs",
        "kind": "event",
        "type": [
            "info"
        ]
    },
    "@timestamp": "2022-07-07T22:42:06.004000Z",
    "dns": {
        "question": {
            "name": "foO-BAR-baz.xYz",
            "registered_domain": "foO-BAR-baz.xYz",
            "top_level_domain": "xYz"
        },
        "response_code": "NoError"
    },
    "observer": {
        "type": "dns",
        "vendor": "Cloudflare"
    },
    "related": {
        "hosts": [
            "foO-BAR-baz.xYz"
        ]
    }
}

Extracted Fields

The following table lists the fields that are extracted, normalized under the ECS format, analyzed and indexed by the parser. It should be noted that infered fields are not listed.

Name Type Description
@timestamp date Date/time when the event originated.
cloudflare.ColoCode keyword IATA airport code of data center that received the request
cloudflare.EDNSSubnet keyword EDNS Client Subnet (IPv4 or IPv6)
cloudflare.EDNSSubnetLength number EDNS Client Subnet length
cloudflare.ResponseCached bool Whether the response was cached or not
dns.question.name keyword The name being queried.
event.category keyword Event category. The second categorization field in the hierarchy.
event.dataset keyword Name of the dataset.
event.kind keyword The kind of the event. The highest categorization field in the hierarchy.
event.type keyword Event type. The third categorization field in the hierarchy.
observer.type keyword The type of the observer the data is coming from.
observer.vendor keyword Vendor name of the observer.
source.ip ip IP address of the source.

Configuration

Create the intake on Sekoia.io

Go to the intake page and create a new intake from the format Cloudflare.

Configure events forwarding on Cloudflare

Retrieve necessary information

First, you will have to retrieve configuration information. Connect to Cloudflare Console to collect the following :

  1. Cloudflare API Token

    • Go to My Profile, then on the left panel, click on API Tokens.
    • Click on the Create Token button and select the Create Custom Token entry.
    • Give a name to your token and set the following permissions:
    Scope Group Level
    Account Account Analytics Read
    Account Logs Read
    Account Logs Edit
    Zone Logs Read
    Zone Logs Edit
    • If you want zerotrust logs you should also add:
    Scope Group Level
    Account Zero Trust Read

    see the Cloudflare documentation

  2. Cloudflare Zone ID :

    • This information is specific to a Website.
    • On the left panel, click on Websites and select the Website you want.
    • On the right panel, there is an API section where you can retrieve the Zone ID.

Create a Logpush job

Configure a Logpush job with the following destination:

https://intake.sekoia.io/plain/batch?header_X-SEKOIAIO-INTAKE-KEY=<YOUR_INTAKE_KEY>

To do so, you can manage Logpush with cURL:

$ curl -X POST https://api.cloudflare.com/client/v4/zones/<CLOUDFLARE_ZONE_ID>/logpush/jobs \
-H "Authorization: Bearer <CLOUDFLARE_API_TOKEN>" \
-H "Content-Type: application/json" \
--data '{
    "dataset": "dns_logs",
    "enabled": true,
    "max_upload_bytes": 5000000,
    "max_upload_records": 1000,
    "logpull_options":"fields=ColoCode,EDNSSubnet,EDNSSubnetLength,QueryName,QueryType,ResponseCached,ResponseCode,SourceIP,Timestamp&timestamps=unix",
    "destination_conf": "https://intake.sekoia.io/plain/batch?header_X-SEKOIAIO-INTAKE-KEY=<YOUR_INTAKE_KEY>"
}' # (1)
  1. will return
    {
      "errors": [],
      "messages": [],
      "result": {
        "id": 148,
        "dataset": "dns_log",
        "enabled": false,
        "name": "<DOMAIN_NAME>",
        "logpull_options": "fields=<LIST_OF_FIELDS>=rfc3339",
        "destination_conf": "https://intake.sekoia.io/plain/batch?header_X-SEKOIAIO-INTAKE-KEY=<YOUR_INTAKE_KEY>",
        "last_complete": null,
        "last_error": null,
        "error_message": null
      },
      "success": true
    }
    

Important

Replace :

  • <YOUR_INTAKE_KEY> with the Intake key you generated in the Create the intake on Sekoia.io step.
  • <CLOUDFLARE_API_TOKEN> with the API Token you generated
  • <CLOUDFLARE_ZONE_ID> with the Zone ID you grabbed
Useful Cloudflare API endpoints

On their documentation, Cloudflare provides a list API endpoints you can use. Find below some useful endpoints:

  • https://api.cloudflare.com/client/v4/zones/<ZONE_ID>/logpush/jobs/<JOB_ID> to verify the job you previously created is correct (you need to specify the JOB_ID)
  • https://api.cloudflare.com/client/v4/zones/<ZONE_ID>/logpush/datasets/<DATASET>/jobs to get all the jobs for a specific dataset (dns_log, firewalls_events or http_requests in our case)
  • https://api.cloudflare.com/client/v4/zones/<ZONE_ID>/logpush/jobs/<JOB_ID> to update a job if you noticed a mistake after the creation of the job (wrong fields, wrong SEKOIA API Key...)