Malicious PDF — malware analysis report

Static analysis result for SHA-256 645d3f82528e950b…

MALICIOUS

PDF

13.3 KB First seen: 2026-05-09
MD5: d5e31a61fa24e06e547efe4f1f9e0f08 SHA-1: 521f67d75f6106ff151dd68eb4c7256039f7797e SHA-256: 645d3f82528e950b261869344320344d0172fa976d1895d4f2a03f769f615df1
70 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF exhibits characteristics of a malicious document, including a malformed active-content stream and an embedded script payload. The ML classifier strongly indicates maliciousness. The embedded file, likely a second-stage payload, is the primary indicator of compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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
  • Embedded script payload in PDF stream info PDF_EMBEDDED_SCRIPT_PAYLOAD
    PDF stream bytes contain an HTML/XFA <script> tag without accompanying Windows shell-execution primitives — common in accessible XFA forms but worth surfacing for analyst review.
  • 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/In PDF document text
    • http://www.xfa.org/schema/xfa-template/2.5/In PDF document text
    • http://www.xfa.org/schema/xfa-data/1.0/In PDF document text

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0008.bin pdf-embedded-file PDF EmbeddedFile object 8 at offset 0xD5 12845 bytes
SHA-256: 3ae99967b080c8b01ceca2345329391d7f33f7f8c1aeb0a45ba9e178b97941ac

Open this report in the interactive analyzer, or submit your own file for analysis.