←back to thread

Ask HN: How to stop an AWS bot sending 2B requests/month?

252 points lgats | 1 comments | 17 Oct 25 05:28 UTC | HN request time: 0.202s | source

I have been struggling with a bot– 'Mozilla/5.0 (compatible; crawler)' coming from AWS Singapore – and sending an absurd number of requests to a domain of mine, averaging over 700 requests/second for several months now. Thankfully, CloudFlare is able to handle the traffic with a simple WAF rule and 444 response to reduce the outbound traffic.

I've submitted several complaints to AWS to get this traffic to stop, their typical followup is: We have engaged with our customer, and based on this engagement have determined that the reported activity does not require further action from AWS at this time.

I've tried various 4XX responses to see if the bot will back off, I've tried 30X redirects (which it follows) to no avail.

The traffic is hitting numbers that require me to re-negotiate my contract with CloudFlare and is otherwise a nuisance when reviewing analytics/logs.

I've considered redirecting the entirety of the traffic to aws abuse report page, but at this scall, it's essentially a small DDoS network and sending it anywhere could be considered abuse in itself.

Are there others that have similar experience?

1. Bender ◴[17 Oct 25 18:27 UTC] No.45620161[source]▶
'Mozilla/5.0 (compatible; crawler)'

Assuming one trusts the user-agent in this case one could reduce the traffic reply to them and avoid touching the disk or any applications in Nginx with something like:

    if ($http_user_agent ~ (crawler|some-other-bot) ) { return 200 '\n\n\n\nBot quota exceeded, check back in 2150 years.\n\n\n\n'; }
There are other variables to look for to see if something is a bot but such things should be very well tested. $http_accept_language, $http_sec_fetch_mode, etc...

I don't use CF but maybe they have a way to block the entire ASN for AWS on your account assuming one does not need inbound connections from them. I just blackhole their CIDR blocks [1] but that won't help someone using a CDN.

[1] - https://ip-ranges.amazonaws.com/ip-ranges.json