Malicious PDF — malware analysis report

Static analysis result for SHA-256 cccdf098966df3f9…

MALICIOUS

PDF

8.0 KB First seen: 2026-05-10
MD5: 8144638a0cd0385a53e132bb51885629 SHA-1: 3dfebab84d4fc893f7d496082e162e149105546d SHA-256: cccdf098966df3f9bdc772d8175bfec1c3b5aa70177699a52a3216a5f6a37ed3
118 Risk Score

Malware Insights

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

The ML classifier strongly indicates maliciousness, supported by heuristics for JavaScript actions and ASCIIHexDecode filters, which are common in PDF exploits. The presence of JavaScript suggests an attempt to execute malicious code, likely to download a second-stage payload or exploit a vulnerability within the PDF reader.

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