Malicious PDF — malware analysis report

Static analysis result for SHA-256 842705f6be0b7f15…

MALICIOUS

PDF

4.8 KB Authoring application: zsrb
MD5: 2b4106254963af5d3212251c29013a0d SHA-1: 587d08e8436c10e68b7024d7e20d47409b893409 SHA-256: 842705f6be0b7f1558ba5f3404cc89c3bcb5c15ea8511f0e9eb6a7c684931e72
62 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The PDF file contains embedded JavaScript, indicated by the 'PDF_EMBEDDED_SCRIPT_PAYLOAD' heuristic and the presence of 'stream_001_off000002b4.js'. This script is likely designed to execute malicious code or download a secondary payload. The ML classifier strongly flagged this PDF as malicious, suggesting a high likelihood of exploitation or payload delivery, consistent with a spearphishing attachment.

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
843f4ef056cad1d5ec63cfc8f21fcf199638d60d7b120d5da8354be9253afab0
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x2B4 42726 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 long base64-like blob(s).