Open redirect: buildingengines.com

name: "Open redirect: buildingengines.com"
description: |
  Detects messages containing buildingengines.com redirect links that use the _redirectTo
  parameter to redirect users to malicious sites. This has been observed in phishing campaigns.
type: "rule"
severity: "medium"
source: |
  type.inbound
  and any(body.links,
          // Look for buildingengines URLs
          .href_url.domain.domain == "app.buildingengines.com"
          and strings.icontains(.href_url.query_params, '_redirectTo=')
          // Make sure it's not redirecting back to buildingengines.com
          and not regex.icontains(.href_url.query_params,
                                  '_redirectTo=(?:https?(?:%3a|:))?(?:%2f|\/){2}[^&]*buildingengines\.com(?:\&|\/|$|%2f)'
          )
  )
  // Exclude legitimate Building Engines domains as senders
  and not sender.email.domain.root_domain == "buildingengines.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: "93df711e-8aea-5bd9-952f-a80d616b0cf0"