Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c0b92af4dbfe351…

MALICIOUS

PDF

23.6 KB
MD5: 9ba968ff16ded0773220ca1e17d97200 SHA-1: 1243b866eaa25cee9046ea4a52cb62077c049ed0 SHA-256: 8c0b92af4dbfe3518d16a845cb30038476646e93b8d67af255d5750e8b45ffa6
120 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

This PDF file was flagged as malicious by an ML classifier with a high confidence score. Static analysis revealed embedded JavaScript, which is often used to exploit vulnerabilities in PDF viewers. The presence of 'PDF_JS_EXPLOIT_CLUSTER' and 'PDF_FROMCHARCODE' heuristics further supports this. The deobfuscated JavaScript likely contains code to download and execute a second-stage payload, although the exact URL or mechanism is not directly extractable from the provided evidence. The benign URLs listed are standard RDF and Adobe namespaces and do not indicate malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 7

  • 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.
  • 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.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • 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.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/xap/1.0/
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/pdf/1.3/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0099_000.js
79028aa17a3d8541e34c536a4fbb01745d9a1187eb3cd645a58ee530698a8d68
pdf-javascript-stream PDF /JS object 99 at offset 0x548D 8741 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 9 long base64-like blob(s).
deobfuscated.js
ee88894d598e83ba1d129aeb024d1722cf989d5c702c2249479e993da905353d
deobfuscated-js PDF JavaScript deobfuscation pass 41313 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 eval/decoder/string-building token(s). Carved artifact contains 18 long base64-like blob(s).