Malicious PDF — malware analysis report

Static analysis result for SHA-256 b334eab3c6aee6f1…

MALICIOUS

PDF

3.4 KB First seen: 2026-05-11
MD5: d781adbdccde9ce8bd39f245c63bcf6d SHA-1: fa71f21719f9973dff7e5a64e85cb9713ae10276 SHA-256: b334eab3c6aee6f15e39c3825d073ae40f7af7e97faa9c3fa9df97ebee574657
118 Risk Score

Malware Insights

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

The ML classifier strongly indicates maliciousness, supported by the presence of JavaScript actions and the use of ASCIIHexDecode filters, which are common in PDF exploits. The combination of these factors suggests the PDF is intended to deliver a malicious payload, likely through an embedded exploit.

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