8 YAMLs for the email cohort per Appendix B: open-relay abuse, mass phishing, phishing-kit X-Mailer signatures, IDN/punycode URLs, sender masquerade, malicious attachment, BEC, encoded payload in body. EmailLifter (E.3.12) consumes by rule_id. test_email_rules.py: YAML-present + inert-in-v0 + xfail(strict) precision case gated on E.3.12.
24 lines
505 B
YAML
24 lines
505 B
YAML
rule_id: R0048
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rule_version: 1
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name: encoded_payload_in_body
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description: |
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Base64-encoded blob ≥ N bytes embedded in the email body —
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classic obfuscated-payload smuggling.
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applies_to:
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- email
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match:
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kind: lifter:email_encoded_payload
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min_bytes: 4096
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encoding: base64
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emits:
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- tactic: TA0011
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technique_id: T1071
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sub_technique_id: T1071.003
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confidence: 0.85
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- tactic: TA0005
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technique_id: T1027
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confidence: 0.9
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evidence_fields:
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- encoded_bytes
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- decoded_preview
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