pascal76/parsedmarc

A Python package and CLI for parsing aggregate and forensic DMARC reports

parsedmarc

parsedmarc is a Python module and CLI utility for parsing DMARC reports. When used with Elasticsearch and Kibana (or Splunk), it works as a self-hosted open source alternative to commercial DMARC report processing services such as Agari Brand Protection, Dmarcian, OnDMARC, ProofPoint Email Fraud Defense, and Valimail.

Features

• Parses draft and 1.0 standard aggregate/rua reports
• Parses forensic/failure/ruf reports
• Can parse reports from an inbox over IMAP
• Transparently handles gzip or zip compressed reports
• Consistent data structures
• Simple JSON and/or CSV output
• Optionally email the results
• Optionally send the results to Elasticsearch and/or Splunk, for use with premade dashboards
• Optionally send reports to Apache Kafka

Resources

DMARC guides

• Demystifying DMARC - A complete guide to SPF, DKIM, and DMARC

SPF and DMARC record validation

If you are looking for SPF and DMARC record validation and parsing, check out the sister project, checkdmarc.

Lookalike domains

DMARC protects against domain spoofing, not lookalike domains. For open source lookalike domain monitoring, check out DomainAware.

CLI help

usage: parsedmarc [-h] [-c CONFIG_FILE] [--strip-attachment-payloads]
                  [-o OUTPUT] [-n NAMESERVERS [NAMESERVERS ...]]
                  [-t DNS_TIMEOUT] [--offline] [-s] [--debug]
                  [--log-file LOG_FILE] [-v]
                  [file_path [file_path ...]]

Parses DMARC reports

positional arguments:
  file_path             one or more paths to aggregate or forensic report
                        files or emails

optional arguments:
  -h, --help            show this help message and exit
  -c CONFIG_FILE, --config-file CONFIG_FILE
                        a path to a configuration file (--silent implied)
  --strip-attachment-payloads
                        remove attachment payloads from forensic report output
  -o OUTPUT, --output OUTPUT
                        write output files to the given directory
  -n NAMESERVERS [NAMESERVERS ...], --nameservers NAMESERVERS [NAMESERVERS ...]
                        nameservers to query (default is Cloudflare's
                        nameservers)
  -t DNS_TIMEOUT, --dns_timeout DNS_TIMEOUT
                        number of seconds to wait for an answer from DNS
                        (default: 2.0)
  --offline             do not make online queries for geolocation or DNS
  -s, --silent          only print errors and warnings
  --debug               print debugging information
  --log-file LOG_FILE   output logging to a file
  -v, --version         show program's version number and exit

Note

In parsedmarc 6.0.0, most CLI options were moved to a configuration file, described below.

Configuration file

parsedmarc can be configured by supplying the path to an INI file

parsedmarc -c /etc/parsedmarc.ini

For example

# This is an example comment

[general]
save_aggregate = True
save_forensic = True

[imap]
host = imap.example.com
user = [email protected]
password = $uperSecure
watch = True

[elasticsearch]
hosts = 127.0.0.1:9200
ssl = False

[splunk_hec]
url = https://splunkhec.example.com
token = HECTokenGoesHere
index = email

The full set of configuration options are:

• general

  • save_aggregate - bool: Save aggregate report data to the Elasticsearch and/or Splunk
  • save_forensic - bool: Save forensic report data to the Elasticsearch and/or Splunk
  • strip_attachment_payloads - bool: Remove attachment payloads from results
  • output - str: Directory to place JSON and CSV files in
  • offline - bool: Do not use online queries for geolocation or DNS
  • nameservers - str: A comma separated list of DNS resolvers (Default: Cloudflare's public resolvers)
  • dns_timeout - float: DNS timeout period
  • debug - bool: Print debugging messages
  • silent - bool: Only print errors (Default: True)
  • log_file - str: Write log messages to a file at this path
  • n_procs - int: Number of process to run in parallel when parsing in CLI mode (Default: 1)
  • chunk_size - int: Number of files to give to each process when running in parallel. Setting this to a number larger than one can improve performance when processing thousands of files

• imap

  • host - str: The IMAP server hostname or IP address
  • port - int: The IMAP server port (Default: 993)
  • ssl - bool: Use an encrypted SSL/TLS connection (Default: True)
  • skip_certificate_verification - bool: Skip certificate verification (not recommended)
  • user - str: The IMAP user
  • password - str: The IMAP password
  • reports_folder - str: The IMAP folder where the incoming reports can be found (Default: INBOX)
  • archive_folder - str: The IMAP folder to sort processed emails into (Default: Archive)
  • watch - bool: Use the IMAP IDLE command to process messages as they arrive
  • delete - bool: Delete messages after processing them, instead of archiving them
  • test - bool: Do not move or delete messages

• elasticsearch

  • hosts - str: A comma separated list of hostnames and ports or URLs (e.g. 127.0.0.1:9200 or https://user:secret@localhost)

    Note

    Special characters in the username or password must be URL encoded.

  • ssl - bool: Use an encrypted SSL/TLS connection (Default: True)
  • cert_path - str: Path to a trusted certificates
  • index_suffix - str: A suffix to apply to the index names
  • monthly_indexes - bool: Use monthly indexes instead of daily indexes
  • number_of_shards - int: The number of shards to use when creating the index (Default: 1)
  • number_of_replicas - int: The number of replicas to use when creating the index (Default: 1)

• splunk_hec

  • url - str: The URL of the Splunk HTTP Events Collector (HEC)
  • token - str: The HEC token
  • index - str: The Splunk index to use
  • skip_certificate_verification - bool: Skip certificate verification (not recommended)

• kafka

  • hosts - str: A comma separated list of Kafka hosts
  • user - str: The Kafka user
  • passsword - str: The Kafka password
  • ssl - bool: Use an encrypted SSL/TLS connection (Default: True)
  • skip_certificate_verification - bool: Skip certificate verification (not recommended)
  • aggregate_topic - str: The Kafka topic for aggregate reports
  • forensic_topic - str: The Kafka topic for forensic reports

• smtp

  • host - str: The SMTP hostname
  • port - int: The SMTP port (Default: 25)
  • ssl - bool: Require SSL/TLS instead of using STARTTLS
  • skip_certificate_verification - bool: Skip certificate verification (not recommended)
  • user - str: the SMTP username
  • password - str: the SMTP password
  • from - str: The From header to use in the email
  • to - list: A list of email addresses to send to
  • subject - str: The Subject header to use in the email (Default: parsedmarc report)
  • attachment - str: The ZIP attachment filenames
  • message - str: The email message (Default: Please see the attached parsedmarc report.)

Warning

It is strongly recommended to not use the nameservers setting. By default, parsedmarc uses Cloudflare's public resolvers, which are much faster and more reliable than Google, Cisco OpenDNS, or even most local resolvers.

The nameservers option should only be used if your network blocks DNS requests to outside resolvers.

Warning

save_aggregate and save_forensic are separate options because you may not want to save forensic reports (also known as failure reports) to your Elasticsearch instance, particularly if you are in a highly-regulated industry that handles sensitive data, such as healthcare or finance. If your legitimate outgoing email fails DMARC, it is possible that email may appear later in a forensic report.

Forensic reports contain the original headers of an email that failed a DMARC check, and sometimes may also include the full message body, depending on the policy of the reporting organization.

Most reporting organizations do not send forensic reports of any kind for privacy reasons. While aggregate DMARC reports are sent at least daily, it is normal to receive very few forensic reports.

An alternative approach is to still collect forensic/failure/ruf reports in your DMARC inbox, but run parsedmarc with save_forensic = True manually on a separate IMAP folder (using the reports_folder option), after you have manually moved known samples you want to save to that folder (e.g. malicious samples and non-sensitive legitimate samples).

Sample aggregate report output

Here are the results from parsing the example report from the dmarc.org wiki. It's actually an older draft of the the 1.0 report schema standardized in RFC 7480 Appendix C. This draft schema is still in wide use.

parsedmarc produces consistent, normalized output, regardless of the report schema.

JSON

{
  "xml_schema": "draft",
  "report_metadata": {
    "org_name": "acme.com",
    "org_email": "[email protected]",
    "org_extra_contact_info": "http://acme.com/dmarc/support",
    "report_id": "9391651994964116463",
    "begin_date": "2012-04-27 20:00:00",
    "end_date": "2012-04-28 19:59:59",
    "errors": []
  },
  "policy_published": {
    "domain": "example.com",
    "adkim": "r",
    "aspf": "r",
    "p": "none",
    "sp": "none",
    "pct": "100",
    "fo": "0"
  },
  "records": [
    {
      "source": {
        "ip_address": "72.150.241.94",
        "country": "US",
        "reverse_dns": "adsl-72-150-241-94.shv.bellsouth.net",
        "base_domain": "bellsouth.net"
      },
      "count": 2,
      "alignment": {
        "spf": true,
        "dkim": false,
        "dmarc": true
      },
      "policy_evaluated": {
        "disposition": "none",
        "dkim": "fail",
        "spf": "pass",
        "policy_override_reasons": []
      },
      "identifiers": {
        "header_from": "example.com",
        "envelope_from": "example.com",
        "envelope_to": null
      },
      "auth_results": {
        "dkim": [
          {
            "domain": "example.com",
            "selector": "none",
            "result": "fail"
          }
        ],
        "spf": [
          {
            "domain": "example.com",
            "scope": "mfrom",
            "result": "pass"
          }
        ]
      }
    }
  ]
}

CSV

xml_schema,org_name,org_email,org_extra_contact_info,report_id,begin_date,end_date,errors,domain,adkim,aspf,p,sp,pct,fo,source_ip_address,source_country,source_reverse_dns,source_base_domain,count,spf_aligned,dkim_aligned,dmarc_aligned,disposition,policy_override_reasons,policy_override_comments,envelope_from,header_from,envelope_to,dkim_domains,dkim_selectors,dkim_results,spf_domains,spf_scopes,spf_results
draft,acme.com,[email protected],http://acme.com/dmarc/support,9391651994964116463,2012-04-27 20:00:00,2012-04-28 19:59:59,,example.com,r,r,none,none,100,0,72.150.241.94,US,adsl-72-150-241-94.shv.bellsouth.net,bellsouth.net,2,True,False,True,none,,,example.com,example.com,,example.com,none,fail,example.com,mfrom,pass

Sample forensic report output

Thanks to Github user xennn for the anonymized forensic report email sample.

JSON

{
     "feedback_type": "auth-failure",
     "user_agent": "Lua/1.0",
     "version": "1.0",
     "original_mail_from": "[email protected]",
     "original_rcpt_to": "[email protected]",
     "arrival_date": "Mon, 01 Oct 2018 11:20:27 +0200",
     "message_id": "<38.E7.30937.BD6E1BB5@ mailrelay.de>",
     "authentication_results": "dmarc=fail (p=none, dis=none) header.from=domain.de",
     "delivery_result": "policy",
     "auth_failure": [
       "dmarc"
     ],
     "reported_domain": "domain.de",
     "arrival_date_utc": "2018-10-01 09:20:27",
     "source": {
       "ip_address": "10.10.10.10",
       "country": null,
       "reverse_dns": null,
       "base_domain": null
     },
     "authentication_mechanisms": [],
     "original_envelope_id": null,
     "dkim_domain": null,
     "sample_headers_only": false,
     "sample": "Received: from Servernameone.domain.local (Servernameone.domain.local [10.10.10.10])\n\tby  mailrelay.de (mail.DOMAIN.de) with SMTP id 38.E7.30937.BD6E1BB5; Mon,  1 Oct 2018 11:20:27 +0200 (CEST)\nDate: 01 Oct 2018 11:20:27 +0200\nMessage-ID: <38.E7.30937.BD6E1BB5@ mailrelay.de>\nTo: <[email protected]>\nfrom: \"=?utf-8?B?SW50ZXJha3RpdmUgV2V0dGJld2VyYmVyLcOcYmVyc2ljaHQ=?=\" <[email protected]>\nSubject: Subject\nMIME-Version: 1.0\nX-Mailer: Microsoft SharePoint Foundation 2010\nContent-Type: text/html; charset=utf-8\nContent-Transfer-Encoding: quoted-printable\n\n<html><head><base href=3D'\nwettbewerb' /></head><body><!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 3.2//EN\"=\n><HTML><HEAD><META NAME=3D\"Generator\" CONTENT=3D\"MS Exchange Server version=\n 08.01.0240.003\"></html>\n",
     "parsed_sample": {
       "from": {
         "display_name": "Interaktive Wettbewerber-Übersicht",
         "address": "[email protected]",
         "local": "sharepoint",
         "domain": "domain.de"
       },
       "to_domains": [
         "domain.de"
       ],
       "to": [
         {
           "display_name": null,
           "address": "[email protected]",
           "local": "peter.pan",
           "domain": "domain.de"
         }
       ],
       "subject": "Subject",
       "timezone": "+2",
       "mime-version": "1.0",
       "date": "2018-10-01 09:20:27",
       "content-type": "text/html; charset=utf-8",
       "x-mailer": "Microsoft SharePoint Foundation 2010",
       "body": "<html><head><base href='\nwettbewerb' /></head><body><!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 3.2//EN\"><HTML><HEAD><META NAME=\"Generator\" CONTENT=\"MS Exchange Server version 08.01.0240.003\"></html>",
       "received": [
         {
           "from": "Servernameone.domain.local Servernameone.domain.local 10.10.10.10",
           "by": "mailrelay.de mail.DOMAIN.de",
           "with": "SMTP id 38.E7.30937.BD6E1BB5",
           "date": "Mon, 1 Oct 2018 11:20:27 +0200 CEST",
           "hop": 1,
           "date_utc": "2018-10-01 09:20:27",
           "delay": 0
         }
       ],
       "content-transfer-encoding": "quoted-printable",
       "message-id": "<38.E7.30937.BD6E1BB5@ mailrelay.de>",
       "has_defects": false,
       "headers": {
         "Received": "from Servernameone.domain.local (Servernameone.domain.local [10.10.10.10])\n\tby  mailrelay.de (mail.DOMAIN.de) with SMTP id 38.E7.30937.BD6E1BB5; Mon,  1 Oct 2018 11:20:27 +0200 (CEST)",
         "Date": "01 Oct 2018 11:20:27 +0200",
         "Message-ID": "<38.E7.30937.BD6E1BB5@ mailrelay.de>",
         "To": "<[email protected]>",
         "from": "\"Interaktive Wettbewerber-Übersicht\" <[email protected]>",
         "Subject": "Subject",
         "MIME-Version": "1.0",
         "X-Mailer": "Microsoft SharePoint Foundation 2010",
         "Content-Type": "text/html; charset=utf-8",
         "Content-Transfer-Encoding": "quoted-printable"
       },
       "reply_to": [],
       "cc": [],
       "bcc": [],
       "attachments": [],
       "filename_safe_subject": "Subject"
     }
   }

CSV

feedback_type,user_agent,version,original_envelope_id,original_mail_from,original_rcpt_to,arrival_date,arrival_date_utc,subject,message_id,authentication_results,dkim_domain,source_ip_address,source_country,source_reverse_dns,source_base_domain,delivery_result,auth_failure,reported_domain,authentication_mechanisms,sample_headers_only
auth-failure,Lua/1.0,1.0,,[email protected],[email protected],"Mon, 01 Oct 2018 11:20:27 +0200",2018-10-01 09:20:27,Subject,<38.E7.30937.BD6E1BB5@ mailrelay.de>,"dmarc=fail (p=none, dis=none) header.from=domain.de",,10.10.10.10,,,,policy,dmarc,domain.de,,False

Bug reports

Please report bugs on the GitHub issue tracker

https://github.com/domainaware/parsedmarc/issues