Malicious PDF — malware analysis report

Static analysis result for SHA-256 cfca151dfa008e8c…

MALICIOUS

PDF

790.6 KB Created: óCÉ4ý¢”kºRfEÐ& … Ä£¿ÒÐ Authoring application: ö”f©²è0þZŽwì^€í茒  ò$
MD5: 97a78e0849bef079ce6942f4ef2513be SHA-1: 67808cb292930f95112e559d5f1069248d6efc0e SHA-256: cfca151dfa008e8c589334b4ad9bfeaef1910468e721de6e8935711cc7926a0b
102 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1553.004 Subversion: Mark-of-the-Web Bypass

The PDF sample was flagged by a machine learning classifier and heuristics indicate the presence of JavaScript, which is used to hide malicious content. The 'PDF_ENCRYPTED_WITH_JS' heuristic suggests that the payload is intentionally obscured from static analysis, likely for evasion. The ML classifier's high score further supports the malicious nature of the file. No specific IOCs were extracted due to the obfuscation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9252

Heuristics 5

  • Encrypted PDF carries /Js — payload hidden from static analysis high PDF_ENCRYPTED_WITH_JS
    PDF declares /Encrypt and also references an executable trigger (/Js). Document encryption hides the JavaScript body and stream contents from static scanners — combined with auto-execution indicators this is a known evasion pattern used to deliver weaponised JavaScript that the analyst cannot inspect without the decryption key.
  • 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.
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic