Detection rules › Sublime MQL

Attachment: Any .sap file (unsolicited)

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

SAP shortcut files can be abused to run unsanctioned code on endpoints. Use if receiving .sap files is not normal behavior in your environment.

Threat classification

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

CategoryValues
Attack typesMalware/Ransomware
Tactics and techniquesEvasion, Scripting

Event coverage

Rule body MQL

type.inbound
and any(attachments, .file_extension == "sap")
and (
  not profile.by_sender().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
)

Detection logic

Scope: inbound message.

SAP shortcut files can be abused to run unsanctioned code on endpoints. Use if receiving .sap files is not normal behavior in your environment.

  1. inbound message
  2. any of attachments where:
    • .file_extension is 'sap'
  3. any of:
    • not:
      • profile.by_sender().solicited
    • profile.by_sender().any_messages_malicious_or_spam
  4. not:
    • profile.by_sender().any_messages_benign
  5. any of:
    • all of:
      • sender.email.domain.root_domain in $high_trust_sender_root_domains
      • not:
        • headers.auth_summary.dmarc.pass
    • sender.email.domain.root_domain not in $high_trust_sender_root_domains

Inspects: attachments[].file_extension, headers.auth_summary.dmarc.pass, sender.email.domain.root_domain, type.inbound. Sensors: profile.by_sender. Reference lists: $high_trust_sender_root_domains.

Indicators matched (1)

FieldMatchValue
attachments[].file_extensionequalssap