Malicious PDF — malware analysis report

Static analysis result for SHA-256 25b3297963074668…

MALICIOUS

PDF

12.6 KB Created: 2011-01-26 13:12:19 Authoring application: nip peg
MD5: aa77dd4977402d281ec3b19e287c66c9 SHA-1: c4d0be7d6c2de1a005569d466055d10f153d36ae SHA-256: 25b32979630746683796aadf39a2575926ff56fd86a30dd297d63358b953a8c0
208 Risk Score

Malware Insights

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

The PDF sample contains XFA form elements with embedded JavaScript that triggers a heap spray exploit. This exploit is designed to execute arbitrary code, likely to download and run a second-stage payload. The ML classifier strongly indicates malicious intent, and the presence of an embedded file further supports this. The document body text is unreadable due to encoding.

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_obj0010.bin
d81baa73e490e4cb879e13927cacd1dd1be37524a37eac51603e15117c578777
pdf-embedded-file PDF EmbeddedFile object 10 at offset 0xCB5 84 bytes
embedded_file_obj0005.bin
24c130f03a4cf51d470b536e94c1e58af67665739e200e0ce198ad41086243c0
pdf-embedded-file PDF EmbeddedFile object 5 at offset 0xD66 228 bytes
embedded_file_obj0003.bin
c97e0522381d6196cc0695f35f4d065f15c9c86a9601a7f776c6afd3f4c6b460
pdf-embedded-file PDF EmbeddedFile object 3 at offset 0xE56 199 bytes
embedded_file_obj0019.bin
7cbbe783cc1d58b1e39858b3ba52b74e06350ace73548db57593ab1aa0fe931f
pdf-embedded-file PDF EmbeddedFile object 19 at offset 0xF47 119 bytes
embedded_file_obj0011.bin
e6c26a3478346d27e841ad49868ebf68bf4c6863b6750e8d60bda3c4c6f79876
pdf-embedded-file PDF EmbeddedFile object 11 at offset 0xFFF 77 bytes
embedded_file_obj0016.bin
92a3ce61d783e15932b5de127ce45a9b4c2f98f4da2453f65241573c1dda808a
pdf-embedded-file PDF EmbeddedFile object 16 at offset 0x10A6 56 bytes
embedded_file_obj0001.bin
c13b424cd98d295c03f5e2fbd8d72d70e33253e63b3f594e9576c0021dc81776
pdf-embedded-file PDF EmbeddedFile object 1 at offset 0x13DF 11474 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).