Detection rules › Sublime MQL

Service abuse: Suspicious Datadog alert

Severity
high
Type
rule
Source
github.com/sublime-security/sublime-rules

Message from alert@dtdg.co containing links to URL shorteners or self-service creation platforms.

Threat classification

Sublime's own taxonomy (not MITRE ATT&CK).

CategoryValues
Attack typesCredential Phishing, Malware/Ransomware
Tactics and techniquesEvasion, Free subdomain host

Event coverage

Rule body MQL

type.inbound
and sender.email.email == "alert@dtdg.co"
and length(body.current_thread.text) < 1000
and (
  (
    any(filter(body.links,
               .parser == "hyperlink"
               and not any(.href_url.query_params_decoded["domain"],
                           strings.parse_domain(.).root_domain == "datadoghq.com"
               )
        ),
        .href_url.domain.root_domain != "datadoghq.com"
        and .href_url.domain.root_domain != "aka.ms"
    )
    and regex.icontains(body.current_thread.text,
                        'quarantine|held for.{0,10}review|secure message|voice\s?mail'
    )
  )
  or (
    ml.nlu_classifier(body.current_thread.text).language == "english"
    and any(ml.nlu_classifier(body.current_thread.text).topics,
            .confidence == "high"
            and .name == "Voicemail Call and Missed Call Notifications"
    )
  )
)

Detection logic

Scope: inbound message.

Message from alert@dtdg.co containing links to URL shorteners or self-service creation platforms.

  1. inbound message
  2. sender.email.email is 'alert@dtdg.co'
  3. length(body.current_thread.text) < 1000
  4. any of:
    • all of:
      • any of filter(body.links) where all hold:
        • .href_url.domain.root_domain is not 'datadoghq.com'
        • .href_url.domain.root_domain is not 'aka.ms'
      • body.current_thread.text matches 'quarantine|held for.{0,10}review|secure message|voice\\s?mail'
    • all of:
      • ml.nlu_classifier(body.current_thread.text).language is 'english'
      • any of ml.nlu_classifier(body.current_thread.text).topics where all hold:
        • .confidence is 'high'
        • .name is 'Voicemail Call and Missed Call Notifications'

Inspects: body.current_thread.text, body.links, body.links[].href_url.query_params_decoded['domain'], body.links[].parser, sender.email.email, type.inbound. Sensors: ml.nlu_classifier, regex.icontains, strings.parse_domain.

Indicators matched (5)

FieldMatchValue
sender.email.emailequalsalert@dtdg.co
body.links[].parserequalshyperlink
regex.icontainsregexquarantine|held for.{0,10}review|secure message|voice\s?mail
ml.nlu_classifier(body.current_thread.text).topics[].confidenceequalshigh
ml.nlu_classifier(body.current_thread.text).topics[].nameequalsVoicemail Call and Missed Call Notifications