Malicious PDF — malware analysis report

Static analysis result for SHA-256 8573458e68b072d5…

MALICIOUS

PDF

4.7 KB
MD5: 05a2662924edf4f215bde0d480011873 SHA-1: bf46188e16093ccb0b116475c3dfd232beddc0a0 SHA-256: 8573458e68b072d59db95b057015209314d48a08b30f72c2639956d65394be6e
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

This PDF file contains embedded JavaScript that is heavily obfuscated using `eval()` and `String.fromCharCode()`. The critical heuristic `PDF_JS_EXPLOIT_CLUSTER` indicates a likely exploit. The JavaScript is designed to download and execute a second-stage payload, as evidenced by the obfuscated code and the presence of a suspicious embedded JavaScript file. The benign URLs related to XFA and Adobe are likely present to avoid detection.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 8

  • 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.
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • 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.
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • 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)
  • 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://ns.adobe.com/xdp/
    • http://www.xfa.org/schema/xci/2.6/
    • http://www.xfa.org/schema/xfa-template/2.6/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0006_000.js
707cb56a793e88aa912caffab8b723a5bd6462e091c26a479569dfa153749cb3
pdf-javascript-stream PDF /JS object 6 at offset 0x224 16532 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
stream_000_off0000012f.bin
69d0d0114b03e3f7748b6bbd5809c83dc8d156e20d1bfcdf9d5925fb9a502f54
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x12F 372 bytes