nella pagina metti, per esempio

codice:
    protected void Page_Load(object sender, EventArgs e)
    {
        if(gl.controlloqs())
            this.Response.Write("Trovata parola pericolosa" + "
");
        
    }
dentro la directory App_Code fai una classe e metti un metodo
codice:
    public static bool controlloqs()
    {
        string pattern = @"banner82|nihaorr1|adw95|xp_|;|--|/\*|<script|</script|ntext|nchar|nvarchar|alter|begin|create|cursor|declare|delete|drop|exec|execute|fetch|insert|kill|open|sys|sysobjects|syscolumns|table|update|varchar";
        return controlloqs(pattern);
    }


    public static bool controlloqs(string pattern)
    {
        bool result = false;

        Regex re = new Regex(pattern, RegexOptions.IgnoreCase | RegexOptions.Multiline);

        foreach (string f in System.Web.HttpContext.Current.Request.QueryString)
        {
            result = re.IsMatch(System.Web.HttpContext.Current.Request.QueryString[f]);
            if (result) break;
        }
        return result;
    }