sublimemediumRule

Twitter infrastructure abuse via link shortener

Email contains Twitter shortened link (t.co) but does not originate from a Twitter domain. This is a known malicious and spam tactic.

MITRE ATT&CK

T1566 T1566.001 T1566.002 T1598 T1204.002 T1486 T1036 T1027 T1598.003

defense-evasioninitial-access

Detection Query

type.inbound
and length(body.links) < 10
and any(body.links, .href_url.domain.root_domain == "t.co")
and sender.email.domain.domain not in~ (
  'twitter.com',
  'x.com',
  'twitter.discoursemail.com'
)
and (
  not profile.by_sender_email().solicited
  or (
    profile.by_sender().any_messages_malicious_or_spam
    and not profile.by_sender().any_messages_benign
  )
)
// 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

Tags

Attack surface reduction

Raw Content

name: "Twitter infrastructure abuse via link shortener"
description: "Email contains Twitter shortened link (t.co) but does not originate from a Twitter domain. This is a known malicious and spam tactic."
type: "rule"
severity: "medium"
source: |
  type.inbound
  and length(body.links) < 10
  and any(body.links, .href_url.domain.root_domain == "t.co")
  and sender.email.domain.domain not in~ (
    'twitter.com',
    'x.com',
    'twitter.discoursemail.com'
  )
  and (
    not profile.by_sender_email().solicited
    or (
      profile.by_sender().any_messages_malicious_or_spam
      and not profile.by_sender().any_messages_benign
    )
  )
  // 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
  )

tags:
  - "Attack surface reduction"
attack_types:
  - "Credential Phishing"
  - "Malware/Ransomware"
  - "Spam"
tactics_and_techniques:
  - "Evasion"
  - "Impersonation: Brand"
  - "Social engineering"
detection_methods:
  - "Content analysis"
  - "Sender analysis"
  - "URL analysis"
id: "99ca165e-086a-5dc0-aa75-82446f27955b"