PDF malware analysis — malicious · 3ac04be4ea98166e

MALICIOUS

PDF

25.3 KB Created: 2011-72-51 03:25:00 Authoring application: String.fromCharCode

MD5: b3424c39fa6fc5b7e59cb9b21ae404ec SHA-1: bd3e3dbadef93de177df7d2d63ea93e0918a82dd SHA-256: 3ac04be4ea98166eabdf77010a2e75512d340fd705baa3b27f0dc05a36ca7c61

94 Risk Score

Malware Insights

MITRE ATT&CK

T1059.001 Command and Scripting Interpreter: PowerShell T1566.002 Phishing: Spearphishing Attachment

The PDF contains JavaScript, specifically using String.fromCharCode, which is a common technique for obfuscating malicious code within PDF documents. The 'PDF_METADATA_EVAL_STAGER' heuristic indicates that the JavaScript is likely used to decode and execute a stager from the PDF's metadata. The ML classifier strongly flags this PDF as malicious. No specific family is identified, but the technique suggests a downloader or initial execution stage.

Machine Learning

Nyx PDF Classifier malicious score 1.0000

Heuristics 4

PDF metadata JavaScript eval stager high PDF_METADATA_EVAL_STAGER

PDF JavaScript reads document metadata fields such as title, subject, or producer, decodes character data with parseInt/String.fromCharCode style helpers, and evals the recovered stage. This is a high-signal exploit-kit staging pattern.
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.
String.fromCharCode low PDF_FROMCHARCODE

String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules.

Extracted artifacts 1

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`javascript_obj0001_000.js` `a39de7529afb2d904383692d3ab4e54b7c4e64d7194a1e22c4770c48991b59bb`	pdf-javascript-stream	PDF /JS object 1 at offset 0x622F	530 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.