Malicious PDF — malware analysis report

Static analysis result for SHA-256 c27c3fa3195bcc49…

MALICIOUS

PDF

4.5 KB Created: 2010-04-30 20:47:26 Authoring application: Fodebarexa
MD5: b9576b82fab8b1354b783932720a2f9b SHA-1: d6e0ad6ef1ff7fbcd6a2963665f053233319fbd0 SHA-256: c27c3fa3195bcc4970485ff7e360cba5b30112508aa3fca5b34f4b8c3676a305
86 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript, identified by the PDF_JAVASCRIPT and PDF_JS heuristics. The PDF_PAGE_WORD_XOR_EVAL_STAGER rule indicates that this JavaScript is obfuscated and designed to be executed as a stager. The ML classifier strongly suggests malicious intent. The embedded JavaScript is likely responsible for downloading and executing a secondary payload, which is a common technique for initial access and further infection.

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
7ad1ee8cba7784f1a95b635244a4165fad123a151fe73c8fc9a0d61755caba74
pdf-javascript-stream PDF /JS object 10 at offset 0xCAB 874 bytes