Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8c18ade82c75d44…

MALICIOUS

PDF

4.5 KB Authoring application: Vabameuaki
MD5: e8a00248d7d8f64514af60deb8c26932 SHA-1: 89f2e03f0fd8cc0e21ff9561bd1c17f6216be09b SHA-256: c8c18ade82c75d44a567bcc62d574fea880320b22061499772573a4afac7f2bc
86 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF file contains embedded JavaScript, flagged by multiple heuristics as a stager. The ML classifier strongly indicates maliciousness. The JavaScript stream, though obfuscated, is likely responsible for downloading and executing a second-stage payload. The presence of PDF-specific stager heuristics points to a common PDF-based malware delivery technique.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 3

  • Page-word XOR JavaScript eval stager high PDF_PAGE_WORD_XOR_EVAL_STAGER
    PDF JavaScript enumerates rendered page words with getPageNthWord/getPageNumWords, extracts encoded byte fragments, XOR-decodes the stage with char-code helpers, and evals the result. This is an old exploit-kit staging pattern and is not normal document JavaScript.
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0011_000.js
1ec398366107a5fedd9bcf18a57f32d68d58e87986c8ad1c876f457b209e2152
pdf-javascript-stream PDF /JS object 11 at offset 0xCA2 815 bytes