Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8e20053fbefaefa…

MALICIOUS

PDF

24.6 KB
MD5: bb991b76eb74d7fbe7ac43761952b8dd SHA-1: b99f0dc7edb068f06f786a8c83c856b7f7aaf9d1 SHA-256: d8e20053fbefaefa5d3e31186224031e9735ca035d36da954a44aabf361759cd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.002 Malicious File

The PDF contains embedded JavaScript, indicated by the PDF_EMBEDDED_SCRIPT_PAYLOAD and PDF_XFA_SCRIPT heuristics. The script utilizes unescape() and String.fromCharCode, suggesting obfuscation to hide its malicious intent. The ML classifier strongly flags this PDF as malicious. The embedded file artifact, embedded_file_obj0008.bin, is likely the secondary payload. The script's primary function appears to be downloading and executing this payload.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 8

  • XFA form contains risky executable script high CVE related PDF_XFA_SCRIPT
    PDF embeds an XFA form whose script block contains exploit, submission/launch, or shell-execution primitives. Ordinary LiveCycle print/update scripts are left as generic XFA/JS signals unless stronger behavior is present.
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits
  • Embedded script payload in PDF stream medium PDF_EMBEDDED_SCRIPT_PAYLOAD
    PDF stream bytes contain an HTML/XFA <script> tag without accompanying Windows shell-execution primitives — common in accessible XFA forms but worth surfacing for analyst review.
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • 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.
  • 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/xfa-template/2.5/
    • http://www.xfa.org/schema/xfa-data/1.0/

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0008.bin
b2ca58cf2542cc27d39362291cd05c540a45434249191e4a95759b34b05f0c4b
pdf-embedded-file PDF EmbeddedFile object 8 at offset 0xC6 24494 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).