从360安全论坛里找到的一段代码，经过整理封装，直接在站点Global.asax文件或写一个HttpModule来拦截恶意请求即可；

http://bbs.webscan.360.cn/forum.php?mod=viewthread&tid=711&page=1&extra=#pid1927

using System.Text.RegularExpressions;
using System.Web;/// <summary>
/// Web请求安全检查：防止跨站点脚本,Sql注入等攻击,来自:http://bbs.webscan.360.cn/forum.php?mod=viewthread&tid=711&page=1&extra=#pid1927
/// 检查数据包括:
/// 1.Cookie
/// 2.当前页面地址
/// 3.ReferrerUrl
/// 4.Post数据
/// 5.Get数据
/// </summary>
public class Safe360
{#region 执行安全检查/// <summary>/// 执行安全检查/// </summary>public static void Procress(){const string errmsg ="<div style='position:fixed;top:0px;width:100%;height:100%;background-color:white;color:green;font-weight:bold;border-bottom:5px solid #999;'><br>您的提交带有不合法参数,谢谢合作!<br><br>了解更多请点击:<a href='http://webscan.360.cn'>360网站安全检测</a></div>";if (RawUrl()){HttpContext.Current.Response.Write(errmsg);HttpContext.Current.Response.End();}if (CookieData()){HttpContext.Current.Response.Write(errmsg);HttpContext.Current.Response.End();}if (HttpContext.Current.Request.UrlReferrer != null){if (Referer()){HttpContext.Current.Response.Write(errmsg);HttpContext.Current.Response.End();}}if (HttpContext.Current.Request.RequestType.ToUpper() == "POST"){if (PostData()){HttpContext.Current.Response.Write(errmsg);HttpContext.Current.Response.End();}}if (HttpContext.Current.Request.RequestType.ToUpper() == "GET"){if (GetData()){HttpContext.Current.Response.Write(errmsg);HttpContext.Current.Response.End();}}}#endregion#region 安全检查正则/// <summary>/// 安全检查正则/// </summary>private const string StrRegex =@"<[^>]+?style=[\w]+?:expression\(|\b(alert|confirm|prompt)\b|^\+/v(8|9)|<[^>]*?=[^>]*?&#[^>]*?>|\b(and|or)\b.{1,6}?(=|>|<|\bin\b|\blike\b)|/\*.+?\*/|<\s*script\b|<\s*img\b|\bEXEC\b|UNION.+?SELECT|UPDATE.+?SET|INSERT\s+INTO.+?VALUES|(SELECT|DELETE).+?FROM|(CREATE|ALTER|DROP|TRUNCATE)\s+(TABLE|DATABASE)";#endregion#region 检查Post数据/// <summary>/// 检查Post数据/// </summary>/// <returns></returns>private static bool PostData(){bool result = false;for (int i = 0; i < HttpContext.Current.Request.Form.Count; i++){result = CheckData(HttpContext.Current.Request.Form[i]);if (result){break;}}return result;}#endregion#region 检查Get数据/// <summary>/// 检查Get数据/// </summary>/// <returns></returns>private static bool GetData(){bool result = false;for (int i = 0; i < HttpContext.Current.Request.QueryString.Count; i++){result = CheckData(HttpContext.Current.Request.QueryString[i]);if (result){break;}}return result;}#endregion#region 检查Cookie数据/// <summary>/// 检查Cookie数据/// </summary>/// <returns></returns>private static bool CookieData(){bool result = false;for (int i = 0; i < HttpContext.Current.Request.Cookies.Count; i++){result = CheckData(HttpContext.Current.Request.Cookies[i].Value.ToLower());if (result){break;}}return result;}#endregion#region 检查Referer/// <summary>/// 检查Referer/// </summary>/// <returns></returns>private static bool Referer(){return CheckData(HttpContext.Current.Request.UrlReferrer.ToString());}#endregion#region 检查当前请求路径/// <summary>/// 检查当前请求路径/// </summary>/// <returns></returns>private static bool RawUrl(){return CheckData(HttpContext.Current.Request.RawUrl);}#endregion#region 正则匹配/// <summary>/// 正则匹配/// </summary>/// <param name="inputData"></param>/// <returns></returns>private static bool CheckData(string inputData){return Regex.IsMatch(inputData, StrRegex);}#endregion
}

在Global.asax里调用的代码：

private void Application_BeginRequest(object sender, EventArgs e)
    {
        Safe360.Procress();

}