Detection rules › Sublime MQL

Service abuse: Roomsy with unrelated body content

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

Detects messages from Roomsy.com with a structured noreply sender pattern that contain content unrelated to travel, transportation, or order confirmations.

Threat classification

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

CategoryValues
Attack typesBEC/Fraud, Credential Phishing
Tactics and techniquesImpersonation: Brand, Social engineering

Event coverage

Rule body MQL

type.inbound
and sender.email.domain.root_domain == "roomsy.com"
and regex.imatch(sender.email.local_part, "noreply[0-9]{5}")
and not any(ml.nlu_classifier(body.current_thread.text).topics,
            .name in ("Travel and Transportation", "Order Confirmations")
)

Detection logic

Scope: inbound message.

Detects messages from Roomsy.com with a structured noreply sender pattern that contain content unrelated to travel, transportation, or order confirmations.

  1. inbound message
  2. sender.email.domain.root_domain is 'roomsy.com'
  3. sender.email.local_part matches 'noreply[0-9]{5}'
  4. not:
    • any of ml.nlu_classifier(body.current_thread.text).topics where:
      • .name in ('Travel and Transportation', 'Order Confirmations')

Inspects: body.current_thread.text, sender.email.domain.root_domain, sender.email.local_part, type.inbound. Sensors: ml.nlu_classifier, regex.imatch.

Indicators matched (4)

FieldMatchValue
sender.email.domain.root_domainequalsroomsy.com
regex.imatchregexnoreply[0-9]{5}
ml.nlu_classifier(body.current_thread.text).topics[].namememberTravel and Transportation
ml.nlu_classifier(body.current_thread.text).topics[].namememberOrder Confirmations