Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d5b0544886c0557…

MALICIOUS

PDF

6.3 KB First seen: 2026-05-10
MD5: 6635b531089d3037475cd84779b5c2f6 SHA-1: 1a63480ce8d3692586046a270435c9b43c5fe4dc SHA-256: 8d5b0544886c05574ee591c82587d500320b23b0703973d649af0118fce2a1ba
148 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF file contains embedded JavaScript, indicated by the PDF_JAVASCRIPT and PDF_JS heuristics. The JavaScript stream is further processed by PDF_UNESCAPE, suggesting obfuscation. While no specific URLs were extracted from the script itself, the presence of an embedded artifact named 'objstm_0024_00.bin' and the JavaScript action point to a likely attempt to download and execute a second-stage payload. The benign URLs present are standard PDF metadata namespaces.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

Heuristics 4

  • JavaScript action low 2 related findings PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules. (matched inside decoded stream)
  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
    Matched line in script
    function RandomVar8(RandomVar9){return unescape(RandomVar9.replace(/ARG/g,'%u'));}
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules. (matched inside decoded stream)
  • 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://www.w3.org/1999/02/22-rdf-syntax-ns# In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/pdf/1.3/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
objstm_0024_00.bin pdf-objstm-decoded PDF /ObjStm 24 0 obj (inflated) 459 bytes
SHA-256: a839c08666d746b8a7887c6bbc04e5ef95bac6cdbd2834b12414dcf0128fcb7b

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