Malicious PDF — malware analysis report

Static analysis result for SHA-256 4cfb3f9e30844266…

MALICIOUS

PDF

29.2 KB Created: 2013-02-04 13:49:43 Authoring application: BVueMyGp (via XWbt14Wq2SGq8) First seen: 2026-05-09
MD5: a883bcfe3ddf7ec7ab7b5626296f4c0c SHA-1: 39c1620994f2d730a3780159f6130b006237f0d3 SHA-256: 4cfb3f9e30844266fbefb219f23b3bc82f4ecb14f975db5929c447a9706c5b29
72 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The PDF file was flagged as malicious by an ML classifier. It contains an embedded file and utilizes XFA forms, which are often used to disguise malicious content or deliver second-stage payloads. The presence of an embedded file, specifically 'embedded_file_obj0016.bin', is a strong indicator of a potential dropper or exploit delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9094

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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0016.bin pdf-embedded-file PDF EmbeddedFile object 16 at offset 0x176A 28171 bytes
SHA-256: 3dc28ed4e4a4e43f36fd32d78703fa8a8b53f1fe53601b527f97ee60ffcee5cd
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
stream_018_off000056aa.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x56AA 120 bytes
SHA-256: 8028c643df4e264224bbf458f3d784a956b1606e3ec50ae4c1280f74a3ecec09