How To Stop Or Block Bots On Website?


Bots are software applications that run automated tasks over the internet. They can perform various functions, such as crawling web pages, sending messages, posting comments, playing games, and more. Bots can be classified into two categories: good bots and malicious bots.

Good bots are those that follow the rules and protocols of the websites they visit, and provide useful services to users and webmasters. For example, search engine crawlers are good bots that index web pages and help users find relevant information. Other examples of good bots are chatbots, social media bots, and weather bots.

Malicious bots are those that violate the rules of the websites they visit, and cause harm or damage to website owners and users. DDoS bots, for example, are malicious bots that flood a website with traffic and make it unavailable to legitimate users. Other types of malicious bots are data scraping bots, carding bots, and spam bots, to mention just a few.

Malicious bots pose serious risks and potential harm to the internet and its users. They can compromise the security, privacy, and performance of websites and online services. They can also manipulate online content, influence public opinion, spread misinformation, and disrupt online communities. Malicious bots can also affect the economy by stealing business and personal data, intellectual property, and revenue from legitimate businesses.

How to Identify Malicious or “Bad” Bots

Malicious bots are automated programs that can harm your website, mobile app, and/or API. They can be used for a variety of attacks such as account takeover, DDoS attacks, ad and payment fraud, web scraping, and several other types of attacks. Detecting and blocking these bots is crucial for protecting your business against online fraud and security threats.

Common traits that can help identify malicious bot activity are:

Unusual Communication Frequency:
Bots tend to communicate continuously with their targets to receive commands, send keep-alive signals, or exfiltrate data. By monitoring the communication frequency between hosts and targets, you can identify patterns that may indicate the presence of a bot.

Unusual Patterns of Page Views:
While humans exhibit relatively predictable patterns of page views, bots, on the other hand, may exhibit unusual patterns of page views that can be indicative of their presence.

Unusual Traffic Origination Patterns:
Bots often use a range of IP addresses to carry out their activities. By monitoring website traffic and blocking the IP addresses accessing your site, you can identify patterns and anomalies that may indicate the presence of a malicious bot.

A Spike in Unsuccessful Log-in Attempts:
Bots may attempt to take over user accounts using breached or stolen credentials. A sudden spike in unsuccessful log-in attempts can be a sign of bot activity.

Bot detection tools from Radware can help block bad bots by using advanced techniques such as behavioral modeling, collective bot intelligence, and fingerprinting. Radware's Bot Manager safeguards web applications, mobile apps, and APIs against automated threats by providing real-time detection and a range of mitigation options. It also includes secure identity and device attestation for native iOS and Android mobile applications to prevent identity spoofing, tampering, and replay attacks.

Why is Monitoring Website Traffic Important?

Monitoring website traffic is important because it provides valuable insights into the behavior of your website visitors. Monitoring traffic helps identify patterns and trends that can help you optimize your website for better user engagement and conversion rates. Continuous monitoring also allows you to quickly identify and address any issues that may arise, such as a sudden drop in traffic or an increase in bounce rates.

There are several tools available that can assist in traffic monitoring. Some popular tools include Google Analytics, CrazyEgg, Kissmetrics and StatCounter. These tools provide businesses with the capabilities necessary to view network traffic, measure network traffic, and analyze network traffic without requiring any former network monitoring experience.

Techniques to Stop or Block Bots

Implementing CAPTCHAs and Challenges

CAPTCHA is an acronym for "Completely Automated Public Turing test to tell Computers and Humans Apart". They are a type of challenge-response test commonly used in computing to determine whether the user is human or not. CAPTCHAs are designed to prevent spam, bot attacks, and data scraping on websites by presenting tasks that are easy for humans but hard for computers. For example, humans can easily read distorted text or identify objects in images, but computers may struggle with these tasks. By requiring users to pass a CAPTCHA test, websites can filter out unwanted traffic and protect their resources and services.

How Effective are CAPTCHAs in Deterring Basic Bots?

CAPTCHAs are not foolproof and can be bypassed by various methods, such as using optical character recognition (OCR) software, hiring human solvers, or exploiting vulnerabilities in the CAPTCHA implementation. However, these methods have their limitations and costs. OCR software may not be able to handle complex or noisy images, human solvers may charge fees or have ethical issues, and vulnerabilities may be patched or rare. Hence CAPTCHAs can still provide a reasonable level of security against basic bots that do not employ these evasive methods.

The effectiveness of CAPTCHAs also depends on their design and difficulty. A poorly designed or too easy CAPTCHA may not pose much of a challenge to bots, while a well-designed or too hard CAPTCHA may frustrate or exclude legitimate human users. Therefore, CAPTCHAs need to balance usability and security, and adapt to the changing capabilities of both humans and bots.

Advanced CAPTCHA Challenges

As bots become more sophisticated and capable of solving traditional CAPTCHAs, such as text or image recognition, new types of CAPTCHAs have emerged to counter them. Some of these new types of CAPTCHAs include:

Interactive Challenges:
These require users to interact with an element on the page, such as clicking a button, moving a slider, or typing a word. These tasks are designed to measure the user's behavior and timing, which can distinguish humans from bots. For example, Google's reCAPTCHA v3 assigns a score to each user based on their interactions with the website, and decides whether to present a further challenge or not.

Puzzle-based CAPTCHAs:
These require users to solve a simple puzzle, such as sliding a piece into a slot, rotating an image, or dragging and dropping items. These tasks are easy for humans but hard for bots to perform without manual intervention or complex algorithms.

Radware’s Crypto Challenge:
Crypto Challenge is a mitigation solution based on the cryptographic proof-of-work concept used in various blockchains. It is designed to deliver continuous, invisible browser-based challenges to suspected bots that automatically and exponentially become more difficult if solved. This challenge-response model creates a 'Cyber Counter Strike' by forcing an attacker's CPU to work harder and longer, thus taking a toll on the attacker's resources. The Crypto Challenge provides a convenient CAPTCHA-free user experience for legitimate users while mitigating sophisticated CAPTCHA-solver and avoider bots. This solution helps protect your website, mobile app, and/or API against automated threats by providing real-time detection and a range of mitigation options.

Rate Limiting and Throttling Requests

Rate limiting and request throttling are techniques used to control the rate at which users can access a website or API. Rate limiting restricts the number of requests that a user can make within a given time frame, while request throttling slows down the rate at which requests are processed. These techniques can be set up to restrict the number of requests from a single IP address within a given time frame. If an IP address exceeds this limit, any additional requests from that IP address will be blocked until the next minute.

While rate limiting and request throttling can be effective in mitigating bot activity, there are potential drawbacks to these techniques. One potential drawback is that they may inadvertently limit genuine users. One such case is when multiple users are accessing your website from the same IP address (such as a shared office or public Wi-Fi network), they may be blocked by the rate limit even though they are not bots. Additionally, some bots may use multiple IP addresses to bypass rate limits, making it more difficult to detect and block them.

Employing Web Application Firewalls (WAF)

A WAF is a security solution that filters and monitors HTTP/HTTPS traffic between a web application and the Internet. It is designed to protect web applications by filtering and monitoring HTTP traffic between a web application and the Internet, and block requests that violate predefined security rules.

Radware offers a range of solutions in this area, including its AppWall WAF and Cloud WAF. AppWall is a WAF that provides full coverage of OWASP Top-10 threats and automatically adapts protections to evolving threats and protected assets. It uses advanced technologies such as machine learning, behavioral analysis, and negative/positive security models to accurately detect and block malicious bot traffic. Radware's Cloud WAF is a cloud-based solution that provides the same level of protection as AppWall, but with the added benefits of scalability, flexibility, and ease of deployment.

Using Specialized Bot Management and Mitigation Solutions

A specialized, dedicated solution like Radware Bot Manager can effectively and accurately block bad bots, leveraging a range of advanced technologies including machine learning, behavioral analysis, and collective bot intelligence. Bot Manager also includes secure identity and device attestation for native iOS and Android mobile applications to prevent identity spoofing, tampering, and replay attacks. Radware Bot Manager defends websites, mobile applications, and/ or APIs against automated threats by providing real-time detection and a range of bot-handling options.

IP Blacklisting and Geofencing

IP blacklisting is a security measure that blocks traffic from specific IP addresses that are known to be associated with malicious activity. This can be an effective way to prevent attacks from known bad actors, but it is not a foolproof solution. Malicious actors can easily change their IP addresses, and legitimate users may be inadvertently blocked if they share an IP address with a blacklisted entity.

Geofencing is the practice of using geographic location data to restrict access to specific content or services. This can be used to block traffic from specific regions that are known to be associated with high levels of malicious activity. An organization could use geofencing to block all traffic from countries that are known to be sources of cyber-attacks, though this is generally considered to be too broad an approach.

While IP blacklisting and geofencing can be effective tools for blocking malicious traffic, there are potential limitations and risks associated with over-reliance on these techniques. One potential limitation is that legitimate users may also be blocked by the blacklist even though they are not malicious actors. Additionally, attackers may use techniques such as IP spoofing or VPNs to bypass these restrictions, making it more difficult to detect and block them.

User Behavior Analysis

By analyzing user behavior, you can identify patterns that are indicative of bot activity. For example, bots may exhibit unusual patterns of page views or communication frequency that can be used to detect their presence.

Device Fingerprinting

Device fingerprinting is the practice of collecting information about a user’s device in order to identify it. This information can be used to detect and block bots that are using spoofed or fake device information.


A honeypot is a security mechanism that is designed to attract and trap bots. By setting up a honeypot on your website, you can lure bots into interacting with it, allowing you to identify and block them.

The Importance of Regularly Updating Security Measures

Bot threats are dynamic in nature and constantly evolving. As technology advances, so do the capabilities of bots, making it necessary for businesses to remain vigilant and stay current with the latest security patches and solutions. This means regularly updating software and systems, as well as implementing the latest security measures to protect against new and emerging threats.

Staying updated with the latest security patches and solutions is crucial for effectively mitigating bot threats. This includes keeping your operating systems, web browsers, and other software current with the latest security patches, as well as implementing the latest security measures such as firewalls, intrusion detection systems, and anti-virus software. By staying informed about the latest threats and taking proactive measures to protect against them, you can help ensure the safety and security of your digital touchpoints.

Radware’s Bad Bot Vulnerability Scanner

Is Your Website Secure Against Bot Attacks? Find Out Now

Already a Customer?

We’re ready to help, whether you need support, additional services, or answers to your questions about our products and solutions.

Get Answers Now from KnowledgeBase
Get Free Online Product Training
Engage with Radware Technical Support
Join the Radware Customer Program

Get Social

Connect with experts and join the conversation about Radware technologies.

Security Research Center