Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4a3e56fb27005c9…

MALICIOUS

PDF

29.0 KB Created: 2013-01-17 17:56:25 Authoring application: xYgKuQjGj (via AgUz0PEHHf6KpFq) First seen: 2026-05-09
MD5: ae968b7b072128c4734b59587c33d42c SHA-1: 06fada454e67248d361e56bb3a0753c67ad4ef7f SHA-256: b4a3e56fb27005c9b454453c7e989a93190ef1155094a5153e822450590a8b71
72 Risk Score

Malware Insights

MITRE ATT&CK
T1557 Adversary-in-the-Middle T1027 Obfuscated Files or Information

The ML classifier strongly flagged this PDF as malicious, and static analysis revealed an embedded file. The PDF structure itself appears to be obfuscated, suggesting an attempt to hide malicious content. The embedded file is the primary indicator of malicious intent, likely serving as a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8760

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://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_obj0012.bin pdf-embedded-file PDF EmbeddedFile object 12 at offset 0x1419 26032 bytes
SHA-256: 42214986d21e63cb0400ac09084b2c3604e862d210f0fd3dff4d675947a3b316
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).