Malicious PDF — malware analysis report

Static analysis result for SHA-256 84cfce41b3c68447…

MALICIOUS

PDF

17.6 KB Created: 2010-08-29 16:19:36 Authoring application: styeZek colSnap
MD5: 7ad829811b68687dcc4e47ba81f20965 SHA-1: d7fa899c8021641b6b6370eba9ddc3fb1787d8da SHA-256: 84cfce41b3c68447634648b5294705b883aa6c71dc5416abb59933b6d16c3ae6
206 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The PDF file contains XFA forms with executable scripts, as indicated by multiple high-severity heuristics including PDF_XFA_SCRIPT and PDF_EVAL. The ML classifier also strongly flagged this PDF as malicious. The ClamAV detection name 'Pdf.Exploit.Dropped-81' suggests it's designed to drop and execute a secondary payload. While no specific URLs or commands were directly extracted, the presence of embedded scripts and the exploit nature points to a downloader or dropper functionality.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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 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)
  • 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/xci/1.0/
    • http://www.xfa.org/schema/xfa-form/2.8/
    • http://www.xfa.org/schema/xfa-template/2.5/
    • http://ns.adobe.com/xtd/
    • http://www.xfa.org/schema/xfa-data/1.0/
    • http://ns.adobe.com/xfdf/

Extracted artifacts 7

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0008.bin
d81baa73e490e4cb879e13927cacd1dd1be37524a37eac51603e15117c578777
pdf-embedded-file PDF EmbeddedFile object 8 at offset 0xDB 84 bytes
embedded_file_obj0009.bin
24c130f03a4cf51d470b536e94c1e58af67665739e200e0ce198ad41086243c0
pdf-embedded-file PDF EmbeddedFile object 9 at offset 0x176 228 bytes
embedded_file_obj0010.bin
eb937c3528afb554a0b15e20d6c423e0ad4264828fbbfeac52f617c93bb2ca92
pdf-embedded-file PDF EmbeddedFile object 10 at offset 0x2B8 976 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 0x534 199 bytes
embedded_file_obj0012.bin
0942afcc256f9a7c8f0d63fce94c240ccbaffc628052a45b337813ab7cd3bbdc
pdf-embedded-file PDF EmbeddedFile object 12 at offset 0x626 34764 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
embedded_file_obj0013.bin
e6c26a3478346d27e841ad49868ebf68bf4c6863b6750e8d60bda3c4c6f79876
pdf-embedded-file PDF EmbeddedFile object 13 at offset 0x41CC 77 bytes
embedded_file_obj0014.bin
92a3ce61d783e15932b5de127ce45a9b4c2f98f4da2453f65241573c1dda808a
pdf-embedded-file PDF EmbeddedFile object 14 at offset 0x425F 56 bytes