Malicious PDF — malware analysis report

Static analysis result for SHA-256 779a2cdc309ef3ae…

MALICIOUS

PDF

162.5 KB
MD5: 6fb5664ce49ad06624a0ea25500205a3 SHA-1: 1fccf9d95d66a53f3eff2ea688823305a64d43d1 SHA-256: 779a2cdc309ef3ae76fe682f0f94307e6775e4bfecc18ee0fe851f74a24b57bd
258 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1203 Exploitation for Client Execution

This PDF file utilizes XFA (XML Forms Architecture) which contains embedded JavaScript. The critical heuristic 'PDF_XFA_HEAP_SPRAY' indicates the presence of exploit code designed to spray the heap, a common technique for achieving arbitrary code execution. The embedded JavaScript, although truncated, contains functions for string manipulation and array initialization, typical of obfuscated exploit code. The ClamAV detection 'Pdf.Exploit.Agent-6136306-0' further confirms its malicious nature, likely involving the execution of a second-stage payload.

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
  • 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.
  • Embedded script payload in PDF stream low 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.
  • 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_0000029a.bin
6dd0596f232b1902c40a59389eb85063905a341c616c73888a99a3ac33fec52c
pdf-embedded-script PDF raw stream script payload at offset 0x29A 165654 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).