We recently got a spike in the requests, all the requests are coming from Alibaba IP address space. We are not sure what the purpose of this request is, the user agent does not identify what tool it is. The request is also coming from many IP addresses, blocking individual IP is challenging as there are so many IPs. After checking some properties of the IP, we see it’s coming from the AS number.

Luckily Cloudflare WAF supports the rule condition based on AS number, applying the new rule based on the AS number helped us mitigated the issue in a few minutes.

Cloudflare has so many features to help us blocking requests from suspicious traffic.

Highly recommend it.