sublimemediumRule

Catbox.moe link from untrusted source

Detects messages containing links to catbox.moe file hosting service from senders who either aren't in highly trusted domains or failed DMARC authentication

MITRE ATT&CK

T1566.001 T1204.002 T1486 T1566 T1598

initial-access

Detection Query

type.inbound
and any(body.links,
        .href_url.domain.root_domain == "catbox.moe"
        and not strings.iends_with(.href_url.path, ".json")
)
// negate highly trusted sender domains unless they fail DMARC authentication
and (
  (
    sender.email.domain.root_domain in $high_trust_sender_root_domains
    and not coalesce(headers.auth_summary.dmarc.pass, false)
  )
  or sender.email.domain.root_domain not in $high_trust_sender_root_domains
)

Data Sources

Email MessagesEmail HeadersEmail Attachments

Platforms

Tags

Attack surface reduction

Raw Content

name: "Catbox.moe link from untrusted source"
description: "Detects messages containing links to catbox.moe file hosting service from senders who either aren't in highly trusted domains or failed DMARC authentication"
type: "rule"
severity: "medium"
source: |
  type.inbound
  and any(body.links,
          .href_url.domain.root_domain == "catbox.moe"
          and not strings.iends_with(.href_url.path, ".json")
  )
  // negate highly trusted sender domains unless they fail DMARC authentication
  and (
    (
      sender.email.domain.root_domain in $high_trust_sender_root_domains
      and not coalesce(headers.auth_summary.dmarc.pass, false)
    )
    or sender.email.domain.root_domain not in $high_trust_sender_root_domains
  )
tags:
 - "Attack surface reduction"
attack_types:
  - "Malware/Ransomware"
tactics_and_techniques:
  - "Free file host"
  - "Social engineering"
detection_methods:
  - "Header analysis"
  - "Sender analysis"
  - "URL analysis"
id: "d6041a8b-55a9-5016-b214-ba021f4eba64"