Malicious PDF — malware analysis report

Static analysis result for SHA-256 9d645f4b6f6eeb63…

MALICIOUS

PDF

11.96 MB Created: «>¯~s4ssï…(n!X ¬çïœGö'LJ³ãévQ`c Authoring application: ¯9£co2g•ÐQh=}udÛõëˆFïnC@˜Á­ (via ¾(¸bys9á¢7/f'D_½æíŒD©qPªÛê½·0)
MD5: 30e7367f46ab8a68888640669fcfc529 SHA-1: 84f3ef2b20217fa4146f5f9e43795ae8432cbf32 SHA-256: 9d645f4b6f6eeb6350d9680f4543044f2a6bce308476822c0234edafa5e453f8
82 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1027 Obfuscated Files or Information T1140 Deobfuscate/Decode Files or Information

The PDF file exhibits characteristics of malicious intent, including heavy obfuscation with a high stream count and the use of JavaScript to hide its content. The presence of JBIG2Decode filter and encrypted content suggests an attempt to evade static analysis. While no specific payload or exploit is directly identified, the overall structure points towards a delivery mechanism for malicious content.

Machine Learning

  • Nyx PDF Classifier clean score 0.0730

Heuristics 4

  • 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.
  • JBIG2Decode filter medium PDF_JBIG2
    JBIG2 image decoder present — historically used in zero-click exploits
  • Unusually high stream count medium PDF_MANY_STREAMS
    PDF contains 501+ stream objects — may indicate heap spray or heavy obfuscation
  • PDF paints image(s) but contains no text operators info PDF_IMAGE_ONLY_LURE
    PDF has 2 image XObject(s) and the content stream contains no text-emitting operators (BT/ET, Tj, TJ, ', ") in either raw bytes or decompressed streams — this is the screenshot-as-PDF pattern used to bypass text-based scanners and to deliver instructions purely through rendered pixels. It is informational unless paired with invisible links or risky URI context.