Malicious PDF — malware analysis report

Static analysis result for SHA-256 37a4084e3b270902…

MALICIOUS

PDF

29.8 KB
MD5: 30fc87cca8800a34f767e29b5c0b16ae SHA-1: 537bc77f86612870372918b117c40cc18499c48b SHA-256: 37a4084e3b270902a82feb8d63dc0d371f03f067efb9c0620ecfb00e36da5073
134 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution: Malicious File

The PDF sample was flagged as malicious by an ML classifier and exhibits multiple heuristic firings related to embedded JavaScript and exploit indicators within decoding filters. The presence of PDF_JAVASCRIPT, PDF_JS, and PDF_FILTER_HEX/85 rules strongly suggests the execution of malicious JavaScript. The ML classifier's high confidence score further supports this assessment. The primary attack pattern involves leveraging PDF vulnerabilities to execute embedded JavaScript, likely for further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • Correlated malicious PDF JavaScript signals critical PDF_CORRELATED_MALICIOUS_JS
    PDF JavaScript or auto-action content is corroborated by exploit staging, ML, or suspicious extracted-artifact findings. This correlation promotes old exploit-kit PDFs that otherwise remain in the suspicious band because each individual signal is intentionally weighted conservatively.
  • ASCIIHexDecode filter (with exploit indicators) medium PDF_FILTER_HEX
    Hex-encoding filter present alongside exploit delivery indicators — often used to hide payload or shellcode bytes
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • ASCII85Decode filter (with exploit indicators) low PDF_FILTER_85
    ASCII85 encoding filter present alongside exploit delivery indicators — uncommon outside of obfuscation