Malicious PDF — malware analysis report

Static analysis result for SHA-256 b54a3ef6ac76f3d1…

MALICIOUS

PDF

6.2 KB Created: 2010-08-29 16:19:36 Authoring application: styeZek colSnap
MD5: c53a78e5ea5c57a84926f628fc973cf3 SHA-1: 5586d1e006993d31dc1506b0e437410505af7e8f SHA-256: b54a3ef6ac76f3d116e873b65c7811395c7d7e36019080fa99d2c2fe01ab8ca0
216 Risk Score

Malware Insights

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

The PDF file contains XFA form elements with embedded executable scripts, a common technique for exploiting PDF vulnerabilities. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of embedded files and the use of eval() and String.fromCharCode() suggest the script is designed to download and execute a secondary payload, likely from one of the embedded URLs.

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
  • 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://www.xfa.org/schema/xfa-template/2.5/
    • http://ns.adobe.com/xtd/
    • 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
78f9631071f03cd2eafd8de565f399d0c62edde5175ed6f90c6215135b7f3b76
pdf-embedded-file PDF EmbeddedFile object 8 at offset 0xDB 134 bytes
embedded_file_obj0010.bin
d4ff871de6628873a7035e48c3dfa9affd8413c4e514b4f2b79a912efb0ddaf9
pdf-embedded-file PDF EmbeddedFile object 10 at offset 0x1AA 712 bytes
embedded_file_obj0011.bin
67c7282b38df59b6436b288a65f84f13910c4a0891bb3c63cd00bc4453f52c26
pdf-embedded-file PDF EmbeddedFile object 11 at offset 0x4BD 464 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
embedded_file_obj0012.bin
103d1e7983cf88bfacedddb4af33ffb5317d9c2c8b3e1bfd987b2c5d712bc985
pdf-embedded-file PDF EmbeddedFile object 12 at offset 0x6D8 323 bytes
embedded_file_obj0014.bin
6f7930ea2bafb35fdc9f4b97b030bd18a866e25d9c0499d1dee5b7df673c6e74
pdf-embedded-file PDF EmbeddedFile object 14 at offset 0x879 12174 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 3 long base64-like blob(s).
embedded_file_obj0015.bin
e6c26a3478346d27e841ad49868ebf68bf4c6863b6750e8d60bda3c4c6f79876
pdf-embedded-file PDF EmbeddedFile object 15 at offset 0x1435 77 bytes
embedded_file_obj0016.bin
92a3ce61d783e15932b5de127ce45a9b4c2f98f4da2453f65241573c1dda808a
pdf-embedded-file PDF EmbeddedFile object 16 at offset 0x14C9 56 bytes