Malicious PDF — malware analysis report

Static analysis result for SHA-256 da27d9555b030bd1…

MALICIOUS

PDF

23.6 KB
MD5: 15242d9a5abeb27d477fc6ab0cdba992 SHA-1: 2db617b0994ba4a5220dfdf3d0cfff5ef3cc55c1 SHA-256: da27d9555b030bd14199f45e1178aa9fde24e9f6fbd1469f189aa92d07c6819f
120 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript, flagged by multiple heuristics including PDF_JAVASCRIPT, PDF_JS, and PDF_JS_EXPLOIT_CLUSTER. The ML classifier also strongly indicates maliciousness. The deobfuscated JavaScript appears to be responsible for downloading and executing a secondary payload, as indicated by the presence of obfuscated code and extracted script files. The specific exploit used is not detailed, but the overall pattern suggests a downloader.

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
5f4124533cbfa2d02b3514a012903cf38117e40daa57484e3502b690c9cfe74c
pdf-javascript-stream PDF /JS object 99 at offset 0x548D 8633 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
349b6bbc8d6d68fd7a5d55b08ccdfae0f6c23e87d4c5addd61beae39963dad2b
deobfuscated-js PDF JavaScript deobfuscation pass 39658 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).