Malicious PDF — malware analysis report

Static analysis result for SHA-256 c08778c70d8e27c6…

MALICIOUS

PDF

23.6 KB
MD5: 096580e274192c15f34ab506294040ec SHA-1: 9e64c2174267577427b1fecd729d48c76673d76f SHA-256: c08778c70d8e27c6bb6ac482ecfff8f604204287d982bbd2db655a94902469b7
120 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by an ML classifier and contains embedded JavaScript. The JavaScript, particularly the deobfuscated version, appears to be designed to download and execute a second-stage payload. The presence of PDF_JS_EXPLOIT_CLUSTER and PDF_FROMCHARCODE heuristics further supports the exploitation of JavaScript within the PDF. No specific family could be identified, but the delivery mechanism is clear.

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
aa30b2d3d1af75c5bfa4b311f16fff1df6625e0030c5e85e72dfc14c90032803
pdf-javascript-stream PDF /JS object 99 at offset 0x548D 8753 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
2f3861c90e3b8ade0ab6050bea27149287d330bb11942f4fc9894da4a5108635
deobfuscated-js PDF JavaScript deobfuscation pass 40361 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).