Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4c9cf0e134ac93b…

MALICIOUS

PDF

8.0 KB First seen: 2026-05-11
MD5: ca2ddd8492d2290bde07f484fba57857 SHA-1: fbdd14d3c0b6ef8703f2cfe24b10f3933cdade74 SHA-256: c4c9cf0e134ac93b721495dbb35443fae1cd580c7adcd01b4be9427eecaaa49f
118 Risk Score

Malware Insights

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

The PDF document was flagged as malicious by an ML classifier with high confidence. Heuristics indicate the presence of JavaScript actions and the use of ASCIIHexDecode filters, which are often employed to obfuscate malicious content within PDFs. These factors suggest the PDF is designed to exploit a vulnerability and potentially execute further malicious code.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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