Malicious PDF — malware analysis report

Static analysis result for SHA-256 319f79f83c4bd9de…

MALICIOUS

PDF

28.9 KB Created: 2013-01-17 17:56:25 Authoring application: xYgKuQjGj (via AgUz0PEHHf6KpFq) First seen: 2013-09-01
MD5: ded44b3cafdaf208a33754519c54d79b SHA-1: 40516bf0e33ad244527bb26b6bdf503bbe64a420 SHA-256: 319f79f83c4bd9deda81ab2698ce1571c03d8b1d990c1b7db5a529d3b1751bf0
72 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1553.005 Mark-of-the-Web Bypass

The ML classifier strongly flagged this PDF as malicious, and static analysis identified an embedded file. The presence of an embedded file suggests the PDF is intended to act as a dropper or exploit delivery mechanism. The specific attack pattern is unclear due to the lack of document body text or script content, but the embedded file is a primary indicator of malicious intent.

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).