Malicious PDF — malware analysis report

Static analysis result for SHA-256 4be9731009a03667…

MALICIOUS

PDF

14.6 KB Created: 2010-10-15 14:23:58 Authoring application: yen vaw
MD5: b5b9b6611dbad7c8d2d02c6d5c5857ed SHA-1: a43bbdf3e5864e7d922c94152f0fb9f564c1701f SHA-256: 4be9731009a036674aeeb0787e1c5363e881f7c9329d7b873c698cba08e3d15b
268 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File

The sample is a PDF file exhibiting critical XFA heap spray and script execution vulnerabilities. Heuristics indicate the presence of unescaped JavaScript and an embedded script payload, strongly suggesting the execution of malicious code. ClamAV detection as Win.Exploit.JS-296 further confirms its malicious nature. The embedded URL is likely part of the exploit chain.

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: Win.Exploit.JS-296 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Exploit.JS-296
  • 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
  • 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://www.xfa.org/schema/xfa-template/2.5/

Extracted artifacts 7

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0002.bin
d81baa73e490e4cb879e13927cacd1dd1be37524a37eac51603e15117c578777
pdf-embedded-file PDF EmbeddedFile object 2 at offset 0xD91 84 bytes
embedded_file_obj0008.bin
24c130f03a4cf51d470b536e94c1e58af67665739e200e0ce198ad41086243c0
pdf-embedded-file PDF EmbeddedFile object 8 at offset 0xE42 228 bytes
embedded_file_obj0019.bin
c97e0522381d6196cc0695f35f4d065f15c9c86a9601a7f776c6afd3f4c6b460
pdf-embedded-file PDF EmbeddedFile object 19 at offset 0xF33 199 bytes
embedded_file_obj0010.bin
31f5aedad71f58cdda2662f0e242f75cc76ccd54d8d2c6562dedfe420c434e1e
pdf-embedded-file PDF EmbeddedFile object 10 at offset 0x1024 119 bytes
embedded_file_obj0018.bin
e6c26a3478346d27e841ad49868ebf68bf4c6863b6750e8d60bda3c4c6f79876
pdf-embedded-file PDF EmbeddedFile object 18 at offset 0x10DB 77 bytes
embedded_file_obj0015.bin
92a3ce61d783e15932b5de127ce45a9b4c2f98f4da2453f65241573c1dda808a
pdf-embedded-file PDF EmbeddedFile object 15 at offset 0x1182 56 bytes
embedded_file_obj0001.bin
a2c0fb07036d782459a5eb0be5fe7fa883155ff54d6e9898088619f71d36353e
pdf-embedded-file PDF EmbeddedFile object 1 at offset 0x14B6 9106 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 6 long base64-like blob(s).