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Create attachment_pdf_base64_javascript_eval.yml #4355

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Create attachment_pdf_base64_javascript_eval.yml #4355

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9b0e32e
Create attachment_pdf_base64_javascript_eval.yml
keaton-sublime Apr 15, 2026
ddd53df
Auto-format MQL and add rule IDs
Apr 15, 2026
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24 changes: 24 additions & 0 deletions detection-rules/attachment_pdf_base64_javascript_eval.yml
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name: "Attachment: PDF with base64 JavaScript and eval functions"
description: "PDF attachment contains base64-encoded JavaScript variables with eval functions, indicating potential code obfuscation and execution techniques commonly used in malicious documents."
type: "rule"
severity: "medium"
source: |
type.inbound
and any(filter(attachments, .file_type == "pdf"),
any(file.explode(.),
.depth == 0
and any(.scan.yara.matches,
.name in ("pdf_b64_js_var_eval", "pdf_acro_js_functions", )
)
)
)
attack_types:
- "Malware/Ransomware"
tactics_and_techniques:
- "Evasion"
- "PDF"
detection_methods:
- "File analysis"
- "Javascript analysis"
- "YARA"
id: "1b1b9c12-5473-546e-ae4e-038e372a02a8"