Malicious PDF — malware analysis report

Static analysis result for SHA-256 0879f562e90f3f73…

MALICIOUS

PDF

6.3 KB Authoring application: Woibneqeni (via e1201Uzenwzijecijawida)
MD5: 116c2b6f86fd3b53a8e97cc183ab5a00 SHA-1: 5ec9785d27a0250cb35f74f505e9a9c869ba7be8 SHA-256: 0879f562e90f3f73a2e49cdb3eb01cb3940b4ba636e4180527e744df0e846378
86 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

This PDF sample contains obfuscated JavaScript that is designed to be evaluated. The script reconstructs a string of hexadecimal byte values and then uses the `eval` function to execute it, likely to download and run a second-stage payload. The ML classifier and heuristics strongly indicate malicious intent.

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_obj0010_000.js
e5fb7241b86520d30618ed164f0373984e043b354e933bd4bfa81c848e06fafc
pdf-javascript-stream PDF /JS object 10 at offset 0x11B0 1464 bytes