Malicious PDF — malware analysis report

Static analysis result for SHA-256 a2ff9df52c14cd19…

MALICIOUS

PDF

103.2 KB
MD5: a58d4069b9ced9c841fafd8e55cdabd4 SHA-1: e36559c15c2140d158f3242d1a52c74c86f9cbf2 SHA-256: a2ff9df52c14cd19cef6b09b4bb6b343c69c7bcad577d48afd33ccd36f4ce7ac
268 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File Execution: Malicious File Execution

The PDF file contains XFA form elements with embedded JavaScript, which is being used to perform a heap spray attack. This is indicated by the PDF_XFA_HEAP_SPRAY and PDF_EMBEDDED_SCRIPT_PAYLOAD heuristics. The script likely downloads and executes a second-stage payload, although the exact mechanism is obfuscated. ClamAV also detected this as Pdf.Exploit.Agent-6136306-0.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 9

  • 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.
  • XFA JavaScript heap-spray exploit code critical PDF_XFA_HEAP_SPRAY
    PDF contains XFA script content with heap-spray or shellcode-like JavaScript markers such as large encoded word sequences, util.pack, large arrays, or spray variable names. This is a weaponised Adobe Reader exploit pattern, not a normal interactive form.
  • ClamAV: Pdf.Exploit.Agent-6136306-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-6136306-0
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution
  • 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.
  • 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_pdf_script_00000298.bin
371aad6a18346a279a06087fd954eddeb872ac3acc4d9e22f415245c6f1d70d8
pdf-embedded-script PDF raw stream script payload at offset 0x298 104949 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).