Malicious PDF — malware analysis report

Static analysis result for SHA-256 d77b2ff7c507ba42…

MALICIOUS

PDF

39.9 KB Created: 2012-12-17 16:05:19 Authoring application: ameuqjcms (via shtqdthq) First seen: 2026-05-07
MD5: 02528e04c43e1d1d19989da80b965201 SHA-1: d08c0f8353a664359dc424cc264d745f2a39b8e3 SHA-256: d77b2ff7c507ba4251ea6a569e12a046377df25eb02aaab8a69db60ef514f6ef
72 Risk Score

Malware Insights

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

The ML classifier strongly indicates maliciousness (0.961860). The PDF contains an embedded file, a common technique for delivering secondary payloads. The XFA form heuristic also fired, suggesting potential exploitation of form-related vulnerabilities. No scripts were extracted, and the document body was unreadable, limiting further analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9619

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_obj0016.bin pdf-embedded-file PDF EmbeddedFile object 16 at offset 0x17E9 7076 bytes
SHA-256: a3e490b4dcf23cb3d6b7149b0221fd2e3882b332f9f1601f9ead01d00c872680
Detection
ClamAV: No threats found
Obfuscation or payload: likely
99 of 198 identifiers look randomly generated (e.g. 'DqmhhrsG0BKIAgEAx') — consistent with name-mangling obfuscation.