Open redirect: Ticketmaster

name: "Open redirect: Ticketmaster"
description: |
  Message contains use of the Ticketmaster open redirect, but the sender is not Ticketmaster. This has been exploited in the wild.
references:
  - "https://www.reddit.com/r/cybersecurity/comments/127q4ny/ticketmaster_systems_exploited_for_phishing/"
type: "rule"
severity: "low"
source: |
  type.inbound
  and any(body.links,
          .href_url.domain.domain == 'links.engage.ticketmaster.com'
          and .href_url.path =~ '/ctt'
  )
  and sender.email.domain.root_domain != 'ticketmaster.com'
  and headers.return_path.domain.root_domain != "ticketmaster.com"
  
  // negate highly trusted sender domains unless they fail DMARC authentication
  and (
    (
      sender.email.domain.root_domain in $high_trust_sender_root_domains
      and not headers.auth_summary.dmarc.pass
    )
    or sender.email.domain.root_domain not in $high_trust_sender_root_domains
  )
tags:
  - "Attack surface reduction"
attack_types:
  - "Credential Phishing"
  - "Malware/Ransomware"
tactics_and_techniques:
  - "Open redirect"
detection_methods:
  - "Sender analysis"
  - "URL analysis"
id: "a5b3901f-e57b-5fb9-a3d7-ee2205cc0c5b"