Malicious PDF — malware analysis report

Static analysis result for SHA-256 fef62c2765f8b6f0…

MALICIOUS

PDF

11.6 KB Created: 2011-02-14 14:25:04 Authoring application: fay fib
MD5: bfae7619811370946b9e8d986758bfbd SHA-1: 1919883fae4753f2d22d7d71c2cb019fe7b956cb SHA-256: fef62c2765f8b6f025cc6b61ad019f3c499e8747629c501e694ae0e50a9cfce2
208 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious File T1059 Command and Scripting Interpreter T1059.007 JavaScript

The PDF sample contains critical XFA heap spray exploit code and embedded script payloads. The ML classifier strongly indicates maliciousness. The exploit targets XFA forms, likely to download and execute a second-stage payload from the embedded file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 7

  • 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.
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
  • 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.

Extracted artifacts 7

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0019.bin
d81baa73e490e4cb879e13927cacd1dd1be37524a37eac51603e15117c578777
pdf-embedded-file PDF EmbeddedFile object 19 at offset 0x9AD 84 bytes
embedded_file_obj0017.bin
24c130f03a4cf51d470b536e94c1e58af67665739e200e0ce198ad41086243c0
pdf-embedded-file PDF EmbeddedFile object 17 at offset 0xA5F 228 bytes
embedded_file_obj0009.bin
c97e0522381d6196cc0695f35f4d065f15c9c86a9601a7f776c6afd3f4c6b460
pdf-embedded-file PDF EmbeddedFile object 9 at offset 0xB4F 199 bytes
embedded_file_obj0014.bin
7b435875d17949ed68211981568a06d9e7e478826f66853d8d3ea4710fb64682
pdf-embedded-file PDF EmbeddedFile object 14 at offset 0xC40 119 bytes
embedded_file_obj0012.bin
e6c26a3478346d27e841ad49868ebf68bf4c6863b6750e8d60bda3c4c6f79876
pdf-embedded-file PDF EmbeddedFile object 12 at offset 0xCF7 77 bytes
embedded_file_obj0006.bin
92a3ce61d783e15932b5de127ce45a9b4c2f98f4da2453f65241573c1dda808a
pdf-embedded-file PDF EmbeddedFile object 6 at offset 0xD9D 56 bytes
embedded_file_obj0002.bin
cd690de875886daddafd009c4a8d502567caf97f6076c651d106ba65cd945376
pdf-embedded-file PDF EmbeddedFile object 2 at offset 0x10D4 11097 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 5 long base64-like blob(s).