Malicious PDF — malware analysis report

Static analysis result for SHA-256 d2a5ac9fb68c375a…

MALICIOUS

PDF

47.9 KB Authoring application: *#"×½5Ó÷s ønV[¶åÞIèÉfÕkTdÇïiµE}ÆhIÔÓËð6¶ (via HR†m?U+#³Ê4³tEú`ÿæD†+o‚¦Ä}$<Àýêá;“,ÞUZÈ N)
MD5: d81ba9c63d45a7962c073b5b7c75b867 SHA-1: 22b46a700604ce3ac094c7be3dbe22409d695af1 SHA-256: d2a5ac9fb68c375a68ebc46c4be3ea092396beb12db4ef81224f736c8214c2d4
114 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1566.001 Spearphishing Attachment T1204.002 Malicious File

The PDF contains embedded JavaScript and is encrypted with JavaScript, indicating an attempt to hide malicious content. The ML classifier strongly flagged this PDF as malicious. The presence of PDF_JAVASCRIPT, PDF_JS, and PDF_FILTER_HEX heuristics further supports the execution of obfuscated JavaScript. The encrypted nature suggests the JavaScript is responsible for decrypting and executing the actual payload, likely a downloader.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 5

  • Encrypted PDF carries /OpenAction — payload hidden from static analysis high PDF_ENCRYPTED_WITH_JS
    PDF declares /Encrypt and also references an executable trigger (/OpenAction). 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.
  • 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.
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic