You can do several things to help manage bots and prevent them from crawling your web and mobile apps and APIs.
Monitor your site for malicious bot traffic
You can gain visibility by monitoring your site for malicious activity. Once you establish a baseline of typical human behavior, you can compare and contrast suspected bot activity. When visitors and accounts reach a threshold of likely bot behavior, you can trigger alerts and automated responses to block them.
Challenge the bots to prove they are human
You can challenge bots to prove they are human when you suspect malicious behavior using a problem that only real people can solve. A CAPTCHA is one example of this, though sophisticated bots can beat those tests. Furthermore, CAPTCHAs often frustrate human users, driving abandonment. Human Challenge, an alternative human verification system, keeps bots out while preserving the user experience.
Limit the rate of bots’ illicit behaviors
You can frustrate malicious bots by limiting the rate of their repetitive behaviors. Bots often make many login or payment attempts in a short amount of time. Rate limiting slows the process, so cybercriminals move to easier targets with quicker payoffs. However, using something like a web application firewall (WAF) to rate-limit traffic is not enough to block bots on its own. WAFs cannot detect bots that piggyback on real users’ identities and mirror their behavior, nor can they recognize botnets that rotate through thousands of different IP addresses to bypass IP-based rules.
Require proof of work
The proof of work (PoW) technique requires computational effort to be expended before logging in, verifying a payment method or executing another task. PoW consumes a large amount of energy and CPU cycles at scale, which places a cost burden on attackers trying to do many fraudulent activities at once. Because of this, PoW makes it expensive for hackers to complete their attacks and disincentivizes them from launching future attacks against your site.
Block the connection
Once you confirm malicious bot activity, you can block bot access using block pages, redirect the malicious traffic or block the internet address responsible for the bot traffic.