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Eve JSON Format


    "timestamp": "2009-11-24T21:27:09.534255",
    "event_type": "alert",
    "src_ip": "",
    "src_port": 1041,
    "dest_ip": "x.x.250.50",
    "dest_port": 80,
    "proto": "TCP",
    "alert": {
        "action": "allowed",
        "gid": 1,
        "signature_id" :2001999,
        "rev": 9,
        "signature": "ET MALWARE Spyware Downloading Ads",
        "category": "A Network Trojan was detected",
        "severity": 1

Common Section

All the JSON log types share a common structure:

{"timestamp":"2009-11-24T21:27:09.534255","event_type":"TYPE", ...tuple... ,"TYPE":{ ... type specific content ... }}

Event types

The common part has a field "event_type" to indicate the log type.


Event type: Alert

Field action

Possible values: "allowed" and "blocked"



Action is set to "allowed" unless a rule used the "drop" action and Suricata is in IPS mode, or when the rule used the "reject" action.

Event type: HTTP


  • "hostname": The hostname this HTTP event is attributed to
  • "url": URL at the hostname that was accessed
  • "http_user_agent": The user-agent of the software that was used
  • "http_content_type": The type of data returned (ex: application/x-gzip)
  • "cookie"

In addition to these fields, if the extended logging is enabled in the suricata.yaml file the following fields are (can) also included:

  • "length": The content size of the HTTP body
  • "status": HTTP statuscode
  • "protocol": Protocol / Version of HTTP (ex: HTTP/1.1)
  • "http_method": The HTTP method (ex: GET, POST, HEAD)
  • "http_refer": The referer for this action

In addition to the extended logging fields one can also choose to enable/add from 47 additional custom logging HTTP fields enabled in the suricata.yaml file. The additional fields can be enabled as following:

  - eve-log:
      enabled: yes
      type: file #file|syslog|unix_dgram|unix_stream
      filename: eve.json
      # the following are valid when type: syslog above
      #identity: "suricata" 
      #facility: local5
      #level: Info ## possible levels: Emergency, Alert, Critical,
                   ## Error, Warning, Notice, Info, Debug
        - alert
        - http:
            extended: yes     # enable this for extended logging information
            # custom allows additional http fields to be included in eve-log
            # the example below adds three additional fields when uncommented
            #custom: [Accept-Encoding, Accept-Language, Authorization]
            custom: [accept, accept-charset, accept-encoding, accept-language,
            accept-datetime, authorization, cache-control, cookie, from,
            max-forwards, origin, pragma, proxy-authorization, range, te, via,
            x-requested-with, dnt, x-forwarded-proto, accept-range, age,
            allow, connection, content-encoding, content-language,
            content-length, content-location, content-md5, content-range,
            content-type, date, etags, last-modified, link, location,
            proxy-authenticate, referrer, refresh, retry-after, server,
            set-cookie, trailer, transfer-encoding, upgrade, vary, warning,
            www-authenticate, x-flash-version, x-authenticated-user]

The benefits here of using the extended logging is to see if this action for example was a POST or perhaps if a download of an executable actually returned any bytes.


Event with non-extended logging:

"http": {
    "hostname": "",
    "url" :"\/jansson\/releases\/jansson-2.6.tar.gz",
    "http_user_agent": "<User-Agent>",
    "http_content_type": "application\/x-gzip" 

Event with extended logging:

"http": {
    "hostname": "",
    "http_user_agent": "<User-Agent>",
    "http_content_type": "application\/json",
    "http_refer": "http:\/\/\/",
    "http_method": "GET",
    "protocol": "HTTP\/1.1",

Event type: DNS


Outline of fields seen in the different kinds of DNS events:
  • "type": Indicating DNS message type, can be "answer" or "query".
  • "id": <needs explanation>
  • "rrname": Resource Record Name (ex: a domain name)
  • "rrtype": Resource Record Type (ex: A, AAAA, NS, PTR)
  • "rdata": Resource Data (ex. IP that domain name resolves to)
  • "ttl": Time-To-Live for this resource record


Example of a DNS query for the IPv4 address of "" (resource record type 'A'):

"dns": {
    "type": "query",
    "id": 16000,
    "rrname": "",

Example of a DNS answer with an IPv4 (resource record type 'A') return:

"dns": {
    "type": "answer",
    "rrname": "",
    "rdata": ""