name: Protocol or Port Mismatch
id: 54dc1265-2f74-4b6d-b30d-49eb506a31b3
version: 2
date: '2020-07-21'
author: Rico Valdez, Splunk
type: batch
datamodel:
- Network_Traffic
description: This search looks for network traffic on common ports where a higher
  layer protocol does not match the port that is being used. For example, this search
  should identify cases where protocols other than HTTP are running on TCP port 80.
  This can be used by attackers to circumvent firewall restrictions, or as an attempt
  to hide malicious communications over ports and protocols that are typically allowed
  and not well inspected.
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
  as lastTime from datamodel=Network_Traffic where (All_Traffic.app=dns NOT All_Traffic.dest_port=53)
  OR ((All_Traffic.app=web-browsing OR All_Traffic.app=http) NOT (All_Traffic.dest_port=80
  OR All_Traffic.dest_port=8080 OR All_Traffic.dest_port=8000)) OR (All_Traffic.app=ssl
  NOT (All_Traffic.dest_port=443 OR All_Traffic.dest_port=8443)) OR (All_Traffic.app=smtp
  NOT All_Traffic.dest_port=25) by All_Traffic.src_ip, All_Traffic.dest_ip, All_Traffic.app,
  All_Traffic.dest_port |`security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`
  | `drop_dm_object_name("All_Traffic")` | `protocol_or_port_mismatch_filter`'
how_to_implement: Running this search properly requires a technology that can inspect
  network traffic and identify common protocols. Technologies such as Bro and Palo
  Alto Networks firewalls are two examples that will identify protocols via inspection,
  and not just assume a specific protocol based on the transport protocol and ports.
known_false_positives: None identified
references: []
tags:
  analytic_story:
  - Prohibited Traffic Allowed or Protocol Mismatch
  - Command and Control
  asset_type: Endpoint
  cis20:
  - CIS 9
  - CIS 12
  kill_chain_phases:
  - Command and Control
  mitre_attack_id:
  - T1048.003
  nist:
  - DE.AE
  - PR.AC
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - All_Traffic.app
  - All_Traffic.dest_port
  - All_Traffic.src_ip
  - All_Traffic.dest_ip
  security_domain: network
