Malicious PDF — malware analysis report

Static analysis result for SHA-256 c34a2521c266fa74…

MALICIOUS

PDF

29.0 KB Created: 2013-01-17 17:56:25 Authoring application: xYgKuQjGj (via AgUz0PEHHf6KpFq) First seen: 2013-09-14
MD5: 1427b24d398098090692863cfed6d307 SHA-1: 9ba9652d23d8b11e382c1d19b14d5b70db30f74a SHA-256: c34a2521c266fa743dd1f7ddbb29f7f91885b99c9c02baedf5298fa3cf8b55cf
72 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF was flagged by an ML classifier as malicious, and it contains an embedded file. The embedded file itself was identified as a suspicious artifact due to a long encoded blob. The exact nature of the embedded file's payload is not clear from static analysis alone, but its presence strongly suggests an attempt to deliver a secondary malicious component.

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).