PDF malware analysis — malicious · 56b137248116dd02

MALICIOUS

PDF

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

MD5: 9daafa292ff05412019601119ca49a80 SHA-1: 403e9670c874c90d90f06da4efcbf87562b96929 SHA-256: 56b137248116dd02fd6d333e25e0508ae36b7eb5214b033660e1fccaca8fdef6

94 Risk Score

Malware Insights

MITRE ATT&CK

T1059.001 PowerShell

The PDF file contains embedded JavaScript, flagged by multiple heuristics including 'PDF_JAVASCRIPT', 'PDF_JS', and 'PDF_METADATA_EVAL_STAGER'. The JavaScript uses 'String.fromCharCode', indicating obfuscation, and is likely used as a stager to download and execute a second-stage payload. The ML classifier also strongly indicates maliciousness. No specific family could be identified.

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` `05feedd57f992f8caae32de40dc4b1e2bdc99efbc323e6c89e1167956bfc4d17`	pdf-javascript-stream	PDF /JS object 1 at offset 0x620B	537 bytes

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