sublimemediumRule

Link: Direct link to riddle.com hosted showcase

Message contains a single link to a Riddle.com hosted showcase which has been observed abused for credential phishing landing

MITRE ATT&CK

T1566 T1566.001 T1566.002 T1598

Detection Query

type.inbound
and length(body.links) < 20
and any(body.links, .href_url.domain.root_domain == "riddle.com")
and length(filter(body.links,
                  .href_url.domain.root_domain == "riddle.com"
                  and strings.istarts_with(.href_url.path, '/view/')
           )
) == 1
// 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
)
and not profile.by_sender_email().any_messages_benign

Data Sources

Email MessagesEmail HeadersEmail Attachments

Platforms

Tags

Attack surface reduction

Raw Content

name: "Link: Direct link to riddle.com hosted showcase"
description: "Message contains a single link to a Riddle.com hosted showcase which has been observed abused for credential phishing landing"
type: "rule"
severity: "medium"
source: |
  type.inbound
  and length(body.links) < 20
  and any(body.links, .href_url.domain.root_domain == "riddle.com")
  and length(filter(body.links,
                    .href_url.domain.root_domain == "riddle.com"
                    and strings.istarts_with(.href_url.path, '/view/')
             )
  ) == 1
  // 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
  )
  and not profile.by_sender_email().any_messages_benign
tags:
 - "Attack surface reduction"
attack_types:
  - "Credential Phishing"
tactics_and_techniques:
  - "Free file host"
detection_methods:
  - "Sender analysis"
  - "URL analysis"
  - "Header analysis"
id: "cca7d2f5-421f-5421-ae13-da5588c15c8b"