Open redirect: mail.spiceworks.com

name: "Open redirect: mail.spiceworks.com"
description: |
  Message contains use of the mail.spiceworks.com redirect. This has been exploited in the wild.
type: "rule"
severity: "medium"
source: |
  type.inbound
  and any(body.links,
          .href_url.domain.domain == "mail.spiceworks.com"
          and strings.icontains(.href_url.query_params,
                                '_externalContentRedirect'
          )
          and not regex.icontains(.href_url.query_params,
                                  '_externalContentRedirect=(?:https?(?:%3a|:))?(?:%2f|\/){2}[^&]*spiceworks\.com(?:\&|\/|$|%2f)'
          )
  )
  and not sender.email.domain.root_domain == "spiceworks.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
  )
attack_types:
  - "Credential Phishing"
  - "Malware/Ransomware"
tactics_and_techniques:
  - "Open redirect"
detection_methods:
  - "Sender analysis"
  - "URL analysis"
id: "eb97defd-e636-56d9-b2de-c5e41947d7e5"