Malicious PDF — malware analysis report

Static analysis result for SHA-256 71474591c5fd5939…

MALICIOUS

PDF

4.8 KB Authoring application: zsrb
MD5: 6cb79a1b262b32415c7ac5b6abc6675f SHA-1: 6254dd8e50246ee4635b553bcff9d1ba9ad8cb7d SHA-256: 71474591c5fd59398182e1a62869852f8d1d9d6b74456ca9aedb3ba0c63a2669
62 Risk Score

Malware Insights

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

The PDF file contains XFA form elements and an embedded JavaScript file, strongly indicating malicious intent. The ML classifier assigned a high probability of maliciousness. The embedded JavaScript is likely responsible for executing a second-stage payload, as suggested by the 'PDF_EMBEDDED_SCRIPT_PAYLOAD' heuristic.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 7

  • 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 low 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.
  • 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.
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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/\
    • http://www.xfa.org/schema/xfa-template/2.5/
    • http://www.xfa.org/schema/xfa-data/1.0/

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_001_off000002b4.js
5868a231efed32ade980b77573c45ed1a6a039771ef033fad6c39e66c5214bf5
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x2B4 42546 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 long base64-like blob(s).