sublimemediumRule

Open redirect: Signature Travel Network

Message contains use of the Signature Travel Network open redirect, but the sender is not Signature Travel Network. This has been exploited in the wild.

MITRE ATT&CK

T1566 T1566.001 T1566.002 T1598

Detection Query

type.inbound
and any(body.links,
        .href_url.domain.root_domain == 'sigtn.com'
        and strings.iends_with(.href_url.path, "emt.cfm")
        and strings.icontains(.href_url.query_params, "link=")
)
and sender.email.domain.root_domain not in (
  'signaturetravelnetwork.com',
  'sigtn.com'
)
and not any(headers.domains, .root_domain == "signaturetravelnetwork.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
)

Data Sources

Email MessagesEmail HeadersEmail Attachments

Platforms

Raw Content

name: "Open redirect: Signature Travel Network"
description: "Message contains use of the Signature Travel Network open redirect, but the sender is not Signature Travel Network. This has been exploited in the wild."
type: "rule"
severity: "medium"
source: |
  type.inbound
  and any(body.links,
          .href_url.domain.root_domain == 'sigtn.com'
          and strings.iends_with(.href_url.path, "emt.cfm")
          and strings.icontains(.href_url.query_params, "link=")
  )
  and sender.email.domain.root_domain not in (
    'signaturetravelnetwork.com',
    'sigtn.com'
  )
  and not any(headers.domains, .root_domain == "signaturetravelnetwork.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"
tactics_and_techniques:
  - "Open redirect"
detection_methods:
  - "Sender analysis"
  - "URL analysis"
id: "c92e3202-4dae-52ce-b9bd-2d7722c8e72d"