I've accepted an answer, but sadly, I believe we're stuck with our original worst case scenario: CAPTCHA everyone on purchase attempts of the crap. Short explanation: caching / web farms make it impossible to track hits, and any workaround (sending a non-cached web-beacon, writing to a unified table, etc.) slows the site down worse than the bots would. There is likely some pricey hardware from Cisco or the like that can help at a high level, but it's hard to justify the cost if CAPTCHA-ing everyone is an alternative. I'll attempt a more full explanation later, as well as cleaning this up for future searchers (though others are welcome to try, as it's community wiki).

情况

这是关于woot.com上的垃圾销售。我是Woot Workshop的总统,Woot Workshop是Woot的子公司,负责设计,撰写产品描述,播客,博客文章,并主持论坛。我使用CSS/HTML,对其他技术几乎不熟悉。我与开发人员密切合作,在这里讨论了所有的答案(以及我们的许多其他想法)。

可用性是我工作的重要组成部分,而让网站变得令人兴奋和有趣则是剩下的大部分工作。这就是下面三个目标的来源。验证码损害了可用性,机器人从我们的垃圾销售中偷走了乐趣和兴奋。

机器人一秒钟就会在我们的首页上猛击数十次屏幕抓取(和/或扫描我们的RSS),以寻找随机垃圾销售。他们一看到这个,就会触发程序的第二阶段登录,点击“我要一个”,填好表格,然后买下这些垃圾。

评价

lc:在stackoverflow和其他使用此方法的站点上,他们几乎总是处理已验证(登录)的用户,因为正在尝试的任务需要这样。

在Woot上,匿名(未登录)用户可以查看我们的主页。换句话说,撞击机器人可以不经过身份验证(除了IP地址之外基本上无法跟踪)。

所以我们又回到了扫描IP, a)在这个云网络和垃圾邮件僵尸的时代是相当无用的,b)考虑到来自一个IP地址的业务数量,捕获了太多无辜的人(更不用说非静态IP isp的问题和试图跟踪它的潜在性能影响)。

还有,让别人给我们打电话是最糟糕的情况。我们能让他们给你打电话吗?

布拉德克:内德·巴切德的方法看起来很酷,但它们是专门设计来击败为网络站点构建的机器人的。我们的问题是机器人是专门用来破坏我们网站的。其中一些方法可能只在很短的时间内有效,直到脚本编写人员将他们的机器人进化为忽略蜜罐,从屏幕上抓取附近的标签名称而不是表单id,并使用支持javascript的浏览器控件。

 

lc再次说道:“当然,除非炒作是你们营销计划的一部分。”是的,绝对是。当物品出现时的惊喜,以及当你设法得到一件物品时的兴奋,可能比你实际得到的垃圾一样重要,甚至更重要。任何消除先到/先得的东西都不利于“赢”的快感。

 

novatrust:就我个人而言,欢迎我们新的机器人霸主。我们实际上提供RSSfeeds,允许第三方应用程序扫描我们的网站的产品信息,但不是在主站HTML之前。如果我的理解正确的话,你的解决方案通过完全牺牲目标1来帮助目标2(性能问题),并放弃机器人将购买大部分垃圾的事实。我给你的回答投了赞成票,因为你最后一段的悲观情绪对我来说是准确的。这里似乎没有什么灵丹妙药。

其余的响应通常依赖于IP跟踪,这似乎是无用的(僵尸网络/僵尸/云网络)和有害的(捕获许多来自相同IP目的地的无辜的人)。

还有其他方法/想法吗?我的开发人员一直在说“让我们只做验证码”,但我希望有更少的侵入性方法,让所有真正想要我们的垃圾的人。

最初的问题

假设你卖的东西很便宜,但有很高的感知价值,而你的数量非常有限。没有人确切地知道你什么时候会卖这个东西。超过一百万人经常来看你卖什么。

你最终会发现脚本和机器人试图通过编程方式[a]找出你何时出售该道具,[b]确保他们是第一批购买该道具的人。这很糟糕,有两个原因:

你的网站被非人类攻击,拖慢了所有人的速度。 编剧最终“赢得”了产品,让常客感到被骗了。

一个看似显而易见的解决方案是为用户在下单前设置一些障碍,但这至少有三个问题:

The user experience sucks for humans, as they have to decipher CAPTCHA, pick out the cat, or solve a math problem. If the perceived benefit is high enough, and the crowd large enough, some group will find their way around any tweak, leading to an arms race. (This is especially true the simpler the tweak is; hidden 'comments' form, re-arranging the form elements, mis-labeling them, hidden 'gotcha' text all will work once and then need to be changed to fight targeting this specific form.) Even if the scripters can't 'solve' your tweak it doesn't prevent them from slamming your front page, and then sounding an alarm for the scripter to fill out the order, manually. Given they get the advantage from solving [a], they will likely still win [b] since they'll be the first humans reaching the order page. Additionally, 1. still happens, causing server errors and a decreased performance for everyone.

另一种解决方案是经常监视ip攻击,阻止它们进入防火墙,或以其他方式阻止它们排序。这个可以解2。和阻止[b],但扫描ip对性能的影响是巨大的,可能会导致更多像1这样的问题。比编剧自己造成的还要严重。此外,云网络和垃圾邮件僵尸的可能性使得IP检查相当无用。

第三个想法,强迫订单表单加载一段时间(比如半秒),可能会减慢快速订单的进度,但同样,脚本编写人员仍然是第一个进入的人,在任何速度下都不会对实际用户造成损害。

目标

将道具卖给非脚本人。 保持网站运行的速度不被机器人减慢。 不要让“正常”用户完成任何任务来证明他们是人类。


当前回答

可能没有一个神奇的银弹来照顾机器人,但这些建议的组合可能有助于阻止他们,并将他们减少到一个更易于管理的数量。 如果您需要对这些建议进行任何澄清,请告诉我:

Any images that depict the item should be either always the same image name (such as "current_item.jpg") or should be a random name that changes for each request. The server should know what the current item is and will deliver the appropriate image. This image should also have a random amount of padding to reduce bots comparing image sizes. (Possibly changing a watermark of some sort to deter more sophisticated bots). Remove the ALT text from these images. This text is usually redundant information that can be found elsewhere on the pages, or make them generic alt text (such as "Current item image would be here"). The description could change each time a Bag of Crap comes up. It could rotate (randomly) between a number of different names: "Random Crap", "BoC", "Crappy Crap", etc... Woot could also offer more items at the "Random Crap" price, or have the price be a random amount between $0.95 and $1.05 (only change price once for each time the Crap comes up, not for each user, for fairness) The Price, Description, and other areas that differentiate a BoC from other Woots could be images instead of text. These fields could also be Java (not javaScript) or Flash. While dependent on a third-party plug-in, it would make it more difficult for the bots to scrape your site in a useful manner. Using a combination of Images, Java, Flash, and maybe other technologies would be another way to make it more difficult for the bots. This would be a little more difficult to manage, as administrators would have to know many different platforms. There are other ways to obfuscate this information. Using a combination of client-side scripting (javascript, etc) and server-side obfuscation (random image names) would be the most likely way to do it without affecting the user experience. Adding some obfuscating Java and/or Flash, or similar would make it more difficult, while possibly minimally impacting some users. Combine some of these tactics with some that were mentioned above: if a page is reloaded more than x times per minute, then change the image name (if you had a static image name suggested above), or give them a two minute old cached page. There are some very sophisticated things you could do on the back end with user behavior tracking that might not take too much processing. You could off-load that work to a dedicated server to minimize the performance impact. Take some data from the request and send it to a dedicated server that can process that data. If it finds a suspected bot, based on its behavior, it can send a hook to another server (front end routing firewall, server, router, etc OR back-end web or content server) to add some additional security to these users. maybe add Java applets for these users, or require additional information from the user (do not pre-fill all fields in the order page, making a different field empty each time randomly, etc).

其他回答

我有一个解决方案(可能)没有列出(因为我还没有读完这里所有的……)

您可以通过浏览器的User Agent字符串跟踪唯一用户。从本质上讲,通过检查哪些信息是可用的“唯一”,你将能够获得足够的信息来区分不同的人(即使是在相同的IP地址上)。

看看EFF写的这篇文章 以及这个网站(也由EFF),将“测试”你的独特只是基于你的用户代理从浏览器。

为了获得更好的唯一性,你可以在唯一性和ip地址的信息位之间进行比较,从而真正得到罪犯/机器人的可能性。


也从EFF签出这个pdf

通过服务器上的iptables(如果是基于Linux的)或使用专用的“路由器”来限制每个IP地址的并发连接

为什么不让首页只是一个图像映射图形(所有一张图片没有标签,标签等)?人类在几乎任何设备上都能轻松阅读和理解,但机器人却无法进行询问。从本质上讲,整个首页都是一个验证码。

ASP.net AJAX控件工具包中的NoBot控件呢?

它做了一些自动javascript请求和计时技巧,以防止机器人在没有用户交互的情况下访问网站。

抱歉,如果这不符合要求,我得打个电话 tl;博士> D

我的解决方案是市场变革和技术变革的结合。

目前,销售垃圾促销袋部分的技术方面被处理为正常的woot销售。促销开始了,人们争相购买,所有的商品都卖光了。用于日常销售的相同统计图表都是用过的垃圾销售。

这里涉及到几个市场目标:

Get customers to visit the site once every day (impluse purchasing). The possiblility of a seeing a bag of crap sale is the reason/reward. Network/viral/gossipy effect where a customer sees a bag of crap sale is on they will IM/EMail/Telephone their friends. There is also what I'd call general "good will". Woot is a really cool place because it occasionally rewards its customers with amazing sales (bag of crap that included a flat panel tv)... AND its done in a fair "first comes first served" manner.

前两个似乎是最重要的。纯粹的访客数量会影响正常交易的销售速度(或销售一空)。传统上,新客户主要是通过口口相传来吸引的,让客户把自己的朋友推荐到woot.com是一种胜利。

所以…我的解决方案是将促销活动的递送方式改为更多的抽奖方式。

偶尔用户可以做一些有趣的事情,看看他们是否有资格得到一袋垃圾。有趣的内容可以是类似“punch The monkey”或Orbitz迷你看球游戏、棒球或曲棍球的愚蠢flash游戏。这里的目标是机器人无法编写脚本的游戏,因此需要相当谨慎。我们的目标也不仅仅是给游戏赢家一袋垃圾……但对所有游戏玩家来说。

The technical core of the game is that at the end of the game a request is made to a server that does an "instant lottery" to determine if the user has won a bag of crap sale opportunity. The server request will need to include something calculated by the game itself (roughly speaking "hash cash"... a complex, CPU cycle consuming, calculation, and hopefully one that is difficult to reproduce). This is to prevent a bot from repeatedly entering the lottery just be querying the lottery server/service.

游戏本身也会随着时间而改变。你可以为万圣节、圣诞节、情人节、复活节等制作特殊事件游戏。还有许多有趣的营销理念可以与woot的“wooiness”相匹配。

If the user wins they can purchase N bags of crap (in a time limited window)... but they can also send N friends a time limited invitation to purchase a bag of crap (good for 24 hours). This provides a super strong network effect... customers will definately tell their friends. Or you could also do it as "buy 1 give 1"... let customers buy up to a total of N but force every second one to be shipped to a friend. The key here is to make the network/gossip effect an full fledged part... help the customer tell the world about the wonderfulness of woot.

促销材料周围袋垃圾销售概念也将需要修改。一袋垃圾多快卖完的图表已经无关紧要了。比如每个月人们有多少次机会购买。有多少人告诉他们的朋友。材料应该微妙地强调这一点,每天去拜访是一个好主意。

你也可以宣传为什么一袋垃圾的销售正在改变。尤其是你免费雇佣了最烂的顾问。