Malicious PDF — malware analysis report

Static analysis result for SHA-256 9ef6a1c35dfdd3b2…

MALICIOUS

PDF

3.4 KB First seen: 2026-05-11
MD5: dce024d9479a65b252c1c0122bf74aea SHA-1: 4946ff99954baf90686ed37a9001e9df533914bb SHA-256: 9ef6a1c35dfdd3b2e6d970314b8ed162a6b1caa5f3a24e25fc8d9c496af6c37e
118 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File

The PDF 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