Malicious PDF — malware analysis report

Static analysis result for SHA-256 6e59b595636db8ff…

MALICIOUS

PDF

43.1 KB
MD5: 5901d961b4f4e81229f29701f0ccc73f SHA-1: bfb5fc39a4a303bcc343353a89677f37cbeffe0d SHA-256: 6e59b595636db8ff552e514af0c2b2cd3548d19ef1f32cb56c7b7d6978de4714
164 Risk Score

Malware Insights

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

The PDF sample contains embedded JavaScript and triggers heuristics related to PDF JavaScript exploits and XFA forms. The embedded JavaScript is heavily obfuscated but appears to be designed to download and execute a secondary payload. The ML classifier strongly indicates maliciousness. The presence of an embedded URL suggests a potential command and control or download location.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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.
  • 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
  • Suspicious extracted artifact medium 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.
  • 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)
  • 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.bitstream.com
    • 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_obj0012_000.js
2fd9380bc42307b29a7f3cd37123d131500a577710cd0850bcc7013f3c3f1ced
pdf-javascript-stream PDF /JS object 12 at offset 0xA0B2 3883 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s). Carved artifact contains 4 long base64-like blob(s). Carved artifact contains 4 long hex-escaped blob(s).
font_00_sfnt_off0000033c.bin
26f3e7c91c76e658576c1bbb605ddb8e33e657870ea2f8ad3b8fe8f80b303358
pdf-font-stream PDF embedded font (sfnt) at offset 0x33C 65932 bytes