Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b42e1a77b9046ab…

MALICIOUS

PDF

5.3 KB Created: 2010-08-29 16:19:36 Authoring application: styeZek colSnap
MD5: cb8c2decb152bac7e27c405d2a083145 SHA-1: 4a9f4336b3dee6cabb1e2643dcf28f9f44525aee SHA-256: 8b42e1a77b9046ab96dfcb1d1a1bfa884b0e90d5aaf63bd266c4f7e90823ed54
216 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1566.001 Spearphishing Attachment T1190 Exploit Public-Facing Application

This PDF file exhibits multiple high-severity heuristic firings, including PDF_EVAL and PDF_XFA_SCRIPT, indicating the presence of executable script content within an XFA form. The ML classifier strongly flags it as malicious, and ClamAV identifies it as 'Pdf.Exploit.Dropped-81'. The embedded scripts and XFA forms are likely used to exploit a vulnerability and download a secondary payload, as suggested by the 'PDF_EMBEDDED_SCRIPT_PAYLOAD' and 'EXTRACTED_FILE_STATIC_TRIAGE' heuristics. The presence of embedded files further supports the dropper/downloader nature of this artifact.

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.
  • ClamAV: Pdf.Exploit.Dropped-81 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Dropped-81
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (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
  • 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. (matched inside decoded stream)
  • 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/xci/1.0/
    • http://ns.adobe.com/xfdf/
    • http://www.xfa.org/schema/xfa-form/2.8/

Extracted artifacts 7

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0008.bin
04462f810d6eacdacecc9d0a5f3f81bebc722af4415e04da19b520338f642b51
pdf-embedded-file PDF EmbeddedFile object 8 at offset 0xDB 67 bytes
embedded_file_obj0009.bin
24c130f03a4cf51d470b536e94c1e58af67665739e200e0ce198ad41086243c0
pdf-embedded-file PDF EmbeddedFile object 9 at offset 0x165 228 bytes
embedded_file_obj0010.bin
9fa6a72f91b734f114dc3cf553d8c211383dc2c37f765c4fc73106f187db9dfe
pdf-embedded-file PDF EmbeddedFile object 10 at offset 0x2A7 998 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
embedded_file_obj0011.bin
c97e0522381d6196cc0695f35f4d065f15c9c86a9601a7f776c6afd3f4c6b460
pdf-embedded-file PDF EmbeddedFile object 11 at offset 0x53B 199 bytes
embedded_file_obj0012.bin
9f17832e0bfb76f056588368e6c6ccc0fad7935e64e4e4420aef25856a9029f9
pdf-embedded-file PDF EmbeddedFile object 12 at offset 0x62D 12822 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
embedded_file_obj0013.bin
e6c26a3478346d27e841ad49868ebf68bf4c6863b6750e8d60bda3c4c6f79876
pdf-embedded-file PDF EmbeddedFile object 13 at offset 0x10B4 77 bytes
embedded_file_obj0014.bin
92a3ce61d783e15932b5de127ce45a9b4c2f98f4da2453f65241573c1dda808a
pdf-embedded-file PDF EmbeddedFile object 14 at offset 0x1148 56 bytes