Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ca5c2d4865caf7e…

MALICIOUS

PDF

27.9 KB Created: 2013-01-29 13:45:06 Authoring application: bDdLHxK31 (via Fgh7EqgVcLT4AhMJ) First seen: 2026-05-09
MD5: 9b9c65c6851a062e4eefa0d74cb2ef47 SHA-1: 2a0ce600f48bac34fe970a89df176b37c876e41c SHA-256: 4ca5c2d4865caf7e165cdcf888e2d0694d960606f212b79c75c58cf690ccdc9b
72 Risk Score

Malware Insights

MITRE ATT&CK
T1566.003 Spearphishing Attachment T1204.002 Malicious File

The PDF document was flagged by a machine learning classifier as malicious with a high confidence score. Static analysis identified an embedded file, which is a common technique for delivering secondary payloads. The document body is heavily obfuscated and does not provide clear user-facing text, suggesting its primary purpose is exploitation rather than social engineering.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9512

Heuristics 6

  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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/ In PDF document text
    • http://www.xfa.org/schema/xci/1.0/In PDF document text
    • http://www.xfa.org/schema/xfa-template/2.2/In PDF document text
    • http://fsf.org/&gtIn PDF document text
    • http://www.xfa.org/schema/xfa-data/1.0/In PDF document text
    • http://ns.adobe.com/xfdf/In PDF document text
    • http://www.xfa.org/schema/xfa-form/2.8/In PDF document text

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0016.bin pdf-embedded-file PDF EmbeddedFile object 16 at offset 0x174F 28815 bytes
SHA-256: be0e68b5274d5f105c6822d4dc506da5b80462a8e5e34591137d3e56a1ae9ae4
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).