Malicious PDF — malware analysis report

Static analysis result for SHA-256 874b3904390f061d…

MALICIOUS

PDF

27.5 KB
MD5: 33f77d680609eb2fa932954c0623200a SHA-1: 723d9608e775afa132b5ebd717e79cf676ce1b3c SHA-256: 874b3904390f061dc7481f7673a0090bdced9f12068561f7d50d098448b4c4cf
134 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File

The PDF contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, and PDF_CORRELATED_MALICIOUS_JS. The ML classifier also strongly flagged this PDF as malicious. The presence of ASCIIHexDecode and ASCII85Decode filters further suggests obfuscation techniques commonly used to hide malicious code within PDF documents. The primary attack vector appears to be exploiting vulnerabilities via the embedded JavaScript.

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