Malicious PDF — malware analysis report

Static analysis result for SHA-256 855fa2d4b5a8e25e…

MALICIOUS

PDF

45.6 KB
MD5: 274f39ffd6f3ae339e26e469c159a980 SHA-1: 0b5aa564759b461a3127a9da8ca7f4bbb38ed48c SHA-256: 855fa2d4b5a8e25e133f3dd9897f48b95f6b59e30ded846e26d7fc000af29271
116 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.002 Malicious File

The PDF file was flagged as malicious by multiple heuristics, including a critical ClamAV detection for obfuscated objects and an ML classifier. The presence of embedded JavaScript, indicated by PDF_JAVASCRIPT and PDF_JS firings, suggests an attempt to execute malicious code. While the document body is unreadable, the JavaScript is the primary mechanism for exploitation, likely downloading and executing a second-stage payload. The specific URLs extracted are related to XFA forms, which are often used in PDF exploits.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9921

Heuristics 5

  • ClamAV: Heuristics.PDF.ObfuscatedNameObject critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Heuristics.PDF.ObfuscatedNameObject
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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.
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • 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/xci/2.6/
    • http://www.xfa.org/schema/xfa-template/2.6/

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0012_000.js
062b56bc1fc8d4ebbe0c3980a440fae66ee18d6654daf48a9a71439580c6f2e8
pdf-javascript-stream PDF /JS object 12 at offset 0xA1F0 4004 bytes