Malicious PDF — malware analysis report

Static analysis result for SHA-256 914cdb697606b5a8…

MALICIOUS

PDF

127.8 KB Created: !Œöká1œøùê°B̝L‡:®ØXÄ[ðëÃiöj>HG³Ý_t¨O±UJ ¾ÑÎHj
MD5: 5457bc21790e72c54060f0e6356dfead SHA-1: 1d464ed0faac8d32a59db02ca10ad660fc97b56f SHA-256: 914cdb697606b5a863eff781a5c9e2673d4f0b4ff0d0677d063788334188e5e8
264 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious JavaScript

The PDF file contains embedded JavaScript and is flagged as an exploit cluster, indicating it's designed to execute malicious code. The critical PDF_JS_EXPLOIT_CLUSTER and high PDF_GENERIC_STAGE_RECOVERY heuristics, along with the ML_NYX_PDF_MALICIOUS flag, strongly suggest this PDF is a malicious downloader. The embedded JavaScript file, 'generic_stage_recovery_000.js', is the primary artifact for delivering the secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 10

  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
  • RichMedia (Flash) high PDF_RICHMEDIA
    PDF contains /RichMedia (Adobe Flash) which is a historic exploit vector
  • Encrypted PDF carries /JavaScript — payload hidden from static analysis high PDF_ENCRYPTED_WITH_JS
    PDF declares /Encrypt and also references an executable trigger (/JavaScript). 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.
  • Generic recovered JavaScript exploit stage high PDF_GENERIC_STAGE_RECOVERY
    Bounded static stage recovery exposed hidden JavaScript through generic transforms such as null-byte collapse, percent decoding, marker replacement, arithmetic character codes, fromCharCode, numeric arrays, numeric-array minus-key decoders, alphabet-index arrays, /Producer half-difference metadata arrays, hex literals, marker-stripped Base64 literals, custom 6-bit XOR table decoders, or repeated-marker hex carriers. This rule is emitted only when the recovered stage contains exploit-like Acrobat JavaScript or shellcode markers.
  • 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.
  • 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
  • PDF paints image(s) but contains no text operators info PDF_IMAGE_ONLY_LURE
    PDF has 1 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
generic_stage_recovery_000.js
5a3d7ba14259bd43d3a05b93179d071f78a1f224e4943c7a73439d905bfb7075
deobfuscated-js generic stage recovery split-literal-normalize from decompressed stream at 0x0 at offset 0x0 130817 bytes