Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b0e3fa12405bfce…

MALICIOUS

PDF

3.4 KB First seen: 2026-05-11
MD5: a4902798690537fb0049d2d2d37af8be SHA-1: 6c3d87e050ab550800857214a2a9cf064307b796 SHA-256: 9b0e3fa12405bfcebb1f4eeeed067b096d7274b251f43c0e08b817950c5e928a
118 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: Malicious JavaScript

The PDF file contains JavaScript actions and uses ASCIIHexDecode filters, indicating an attempt to obfuscate malicious content. The ML classifier strongly flags this PDF as malicious. While no specific family is identified, the techniques suggest an exploit delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 3

  • JavaScript action low 1 related finding PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • PDF JavaScript rebuilds a builtin via replace() to run a char-code array critical PDF_JS_REPLACE_OBFUSCATED_CHARCODE_BUILDER
    Decoded PDF JavaScript resolves a String builtin from a junked literal — e.g. String['eQvoaol3'.replace(/[3oQS5]/g,'')] yielding fromCharCode/eval — and feeds a large numeric char-code array through it to rebuild and execute the next stage. Dynamically reconstructing a builtin name by stripping junk characters has no benign purpose; paired with the char-code payload array it is an unambiguous obfuscated-JavaScript exploit dropper.
  • ASCIIHexDecode filter (with exploit indicators) medium PDF_FILTER_HEX
    Hex-encoding filter present alongside exploit delivery indicators — often used to hide payload or shellcode bytes