Attachment: PDF with embedded Javascript

name: "Attachment: PDF with embedded Javascript"
description: |
  PDF contains embedded Javascript.
references:
  - "https://delivr.to/payloads?id=f1a0c398-995c-4ea3-9404-0b7b27792e8d"
type: "rule"
severity: "medium"
source: |
  type.inbound
  and any(attachments,
          .file_extension == "pdf"
          and any(file.explode(.),
                  (
                    (any(.scan.strings.strings, strings.icontains(., '/JavaScript')))
                    and (any(.scan.strings.strings, strings.icontains(., '/JS (')))
                  )
          )
  )

  and (
    (
      profile.by_sender().prevalence in ("new", "outlier")
      and not profile.by_sender().solicited
    )
    or (
      profile.by_sender().any_messages_malicious_or_spam
      and not profile.by_sender().any_false_positives
    )
  )

  // negate highly trusted sender domains unless they fail DMARC authentication
  and (
    (
      sender.email.domain.root_domain in $high_trust_sender_root_domains
      and (
        any(distinct(headers.hops, .authentication_results.dmarc is not null),
            strings.ilike(.authentication_results.dmarc, "*fail")
        )
      )
    )
    or sender.email.domain.root_domain not in $high_trust_sender_root_domains
  )
  
tags:
  - "Attack surface reduction"
attack_types:
  - "Malware/Ransomware"
tactics_and_techniques:
  - "Evasion"
  - "Scripting"
detection_methods:
  - "File analysis"
id: "d4cde94f-d9e5-527a-9192-da09f3d21275"