What is a bot? A Guide to Bots

A bot is a software program that imitates human actions by using algorithms to automate tasks such as responding to messages, processing data, or making decisions. By imitating human behavior, bots can be deployed to conduct tasks at high speed and massive scale.

If you use the internet to purchase products, research travel deals, or engage with financial services, chances are highly likely you will encounter bots. Here are some common examples of bots:

• Search engine web crawlers for enhanced indexing
• Chatbots for customer service
• Virtual assistants for boosting productivity

Web crawlers, chatbots, and virtual assistants are good bots. But there are also bad bots, which are malicious automated programs designed to perform harmful activities, such as scraping data, spamming, and more. Bad bots are an ever-evolving issue across many industries, especially for the financial services industry. With this industry having the highest volume of bad bot attacks, the percentage of attempted attacks had increased more than 130% from 2023 to 2024.

Both good and bad bots can contaminate web engagement data and skew analytics. Unfortunately, with more bad bots in operation than good ones, the number of postlogin compromises more than doubled year-over-year, and fake account creation attempts increased, by more than 360% Therefore, investing in intelligent bot management strategies is critical for digital businesses to protect themselves from damaging bot attacks and to discern between good bot and bad bot traffic.

Bots can be programmed to execute various tasks, such as scanning content, interacting with web pages and social media accounts, or chatting with users. 

Simple bots, known as rules-based bots, follow a set of programmed instructions to respond to specific inputs, such as answering FAQs or executing repetitive actions. These bots rely on decision trees and if-then logic, making them effective for structured tasks, but limited in adaptability. More sophisticated bots are beginning to incorporate machine learning (ML) to identify patterns and adapt their behavior based on historical data. While not yet the norm, these approaches allow bots to become more responsive over time, potentially handling more nuanced tasks without manual rule-setting.

AI and natural language processing are being explored to enhance bot functionality. The use of AI in bots continues to evolve as these systems aim to help bots interpret language, derive intent, and simulate more human-like actions. 

Bot Management Tools

So, how can individuals and business owners detect bots, and more importantly, mitigate their negative effects?

Bot management tools are one resource they have to help fight back. These specialized security solutions are designed to identify, monitor, and control bot activity on websites, applications, and networks. They use advanced algorithms, behavioral analysis, machine learning, and challenge-response mechanisms like CAPTCHAs to differentiate between legitimate bots (such as search engine crawlers) and malicious bots (such as credential-stuffing bots or web scrapers). Organizations use bot management tools to prevent fraud, protect sensitive data, and ensure optimal website performance by blocking harmful bot traffic while allowing beneficial automation.

As automation technology continues to advance, bots have become essential tools in customer service, business operations, and even cybersecurity. For instance, many companies deploy AI-driven chatbots to assist customers 24/7, while process automation bots help teams manage repetitive tasks like invoicing and inventory tracking. 

On the other hand, cybercriminals exploit bots for malicious purposes, using them for fraud, credential stuffing, and DDoS attacks. By exploring the most common types of bots, businesses can better understand how to use them strategically while defending against their potential risks.

Some of the most commonly used types of bots include:

• Customer service bots: Interact with customers, providing instant responses, troubleshooting, and assistance in real-time.
• Transaction bots: Automatically complete online transactions, frequently being leveraged by retailers or marketplaces to manage product purchases or stock updates.
• Social media bots: Automate actions on social media platforms, such as liking, following, or posting content.
• Web scraping bots: Collect data from websites, often being used for price comparison, market research, or content aggregation.
• Search engine crawlers: Bots like Googlebot that index websites to make them discoverable in search engines.
• Spambots: Malicious bots that flood websites or social media with unwanted, often irrelevant, content or advertisements.
• Credential-stuffing bots: Automate the process of trying stolen usernames and passwords to gain unauthorized access to accounts.
• DDoS bots: Used to overwhelm a server, network, or website with traffic, causing it to crash or become unavailable.
• Malware bots: Leveraged by cybercriminals to distribute malicious software, steal data, or infiltrate systems.
• AI agents: Autonomous software powered by AI, often used to simulate human interactions, automate research, or generate content across digital platforms.
• LLM crawlers: Bots designed to scrape web content for large language model training or real-time input generation, raising concerns about data ownership and consent.

Bad bots can perform various malicious tasks that can lead to data breaches, identity theft, lost customer conversions, and other undesirable outcomes for digital businesses and web users. For example, bad bots can help fraudsters break into online accounts using stolen usernames and passwords in what is called an account takeover (ATO) attack.

Competitors might unleash bad bots looking to scrape content from your website. This content includes pricing information, competitive offers, and breaking news articles. Bad bots can also be used to spam forums with messages, create millions of fake leads, conduct abandonment campaigns on e-commerce checkout portals, distort marketing analytics, and steal store credits and gift cards. When bots make thousands of visits to a business’s website, they can cause latency and slow the web page down for genuine users.

As bot detection has matured, so have bad bots. Bots can mirror human users in their behavior, making them extremely difficult for security operations teams to detect and block. In order for digital businesses to be competitive, conventional solutions like web application firewalls (WAFs) are no longer enough. This is why demand for bot management solutions is growing at such a rapid pace.

One of the primary issues that businesses face when using bots is misinterpreted rules or logic, which typically leads to incorrect actions, such as improper data entries or responding inappropriately to customer queries. Additionally, bots are frequently used for malicious activities such as spamming and the scraping of content, while those used for fraud, like credential-stuffing bots, can cause significant financial and reputational damage by compromising sensitive data.

Bots can also strain server performance and consume resources meant for legitimate users. DDoS bots, for example, overwhelm a website or server with fake traffic, causing slowdowns, crashes, or downtime, which can result in lost revenue and a poor customer experience. Even ‘good’ bots, such as SEO crawlers, can place unnecessary load on site infrastructure. It’s a best practice to manage their access using tools like robots.txt or through a dedicated bot management solution to mitigate this.

Meanwhile, in the advertising space, bots are commonly used for ad fraud, where they generate fake clicks or views on ads, leading to wasted advertising budgets and skewed campaign analytics. This type of fraud makes it difficult for advertisers to determine the true effectiveness of their campaigns, ultimately wasting resources and potentially harming their return on investment (ROI).

Malicious bot attacks have surged in recent years, posing significant threats to online organizations by damaging brand reputation, reducing revenue, and increasing the risk of data breaches. In fact, in 2024, HUMAN flagged over 215 billion scraping attacks. This rise in bot activity has led to substantial financial losses.

So, how do business owners overcome these challenges? The first step is knowing what they’re up against. Here are a few common bad bots and their attack techniques:

Account Takeover (ATO)

Fraudsters use various techniques to take control of user accounts, a process known as account takeover (ATO).  One common method is credential stuffing, where fraudsters deploy bots armed with stolen username and password credentials to target the sign-in page of online accounts, such as an e-commerce, bank, or email account. ATO attacks affect any organization with a customer-facing login. Common targets include online gaming, retailers, financial services firms, and travel merchants.

Due to the diverse forms of fraud that cybercriminals can commit from compromised accounts, ATO attacks are one of the fastest-growing attack techniques. Successful ATO attacks result in data breaches, identity theft and fraudulent purchases, costing online businesses millions.

Carding and Credit Card Stuffing

In carding attacks, bots test stolen credit or debit card information on merchant sites with small purchases to avoid detection. When small purchases are successful and the card is proven valid, the card data is used to retrieve funds from associated accounts or to purchase gift cards or goods that can be quickly converted to cash. Even when fraudulent transaction attempts are unsuccessful, businesses receive charged card authorization fees for card-not-present transactions, racking up card validation costs of up to 10 cents for each transaction attempt. When you consider that carding bots initiate tens of thousands of transaction attempts, this can cost merchants a significant amount of money.

While carding attacks are similar to ATO attacks, the big difference is that ATO attacks focus on the login page using stolen usernames and passwords, while carding attacks focus on the checkout page using stolen card information.

Scraping

With scraping, or data harvesting, bots are used to crawl web pages to steal prices, content, product reviews, and inventory data. This information can be used to inform a competitor’s business strategy, or to be resold or reposted with the aim of capturing and redirecting users to another website.

Denial of Inventory

Denial of inventory is a form of product inventory hoarding, where fraudsters use automated bots to hold items in digital carts without completing the sale. This is done with the intention of making the item, usually a high-demand or limited-availability item, unavailable to others. Often, the checkout process is never completed, preventing real users from actually purchasing the item, leaving the merchant with low sales and a large inventory.

Scalping

With scalping, bots rapidly buy high-demand and limited-availability items, such as sneakers or concert tickets. The bots used in these attacks are sometimes even referred to as sneaker bots, due to their prevalent use in sought-after sneaker releases. Once a merchant’s inventory is liquidated, fraudsters sell the scarce items in secondary markets at much higher prices.

Effectively detecting and mitigating bad bots is critical for achieving success in the digital space. The ability to identify bad bot traffic from good is key. Telling signs that your business is falling victim to bad bots may include the following:

Large number of login failures

If you notice a sudden spike in login failures, you are likely under attack from ATO bots. Fraudsters typically buy a list of credentials from the dark web and deploy an army of bots to test these credentials on popular travel, social media, and e-commerce sites.

Spike in account creations

An unexpected rise in new customer accounts could indicate bots, not new customers. Another type of account abuse, known as fake account creation, occurs when bots create new accounts that are not linked to real users. Fake accounts are leveraged for other attacks or fraudulent transactions.

Gift card or point validation failures

Seeing a rapid rise in gift card validation failures often indicates a carding attack. In this circumstance, bots are trying to identify which gift cards have large balances, so they can be sold on the dark web.

Increased shopping cart abandonment

If you see a spike in items left in shopping carts without completing the sale, bots may be the culprit, and you may be the victim of denial of inventory attack.

Your content on a strange website

If your content, breaking story, or promotional offer mysteriously appears on unapproved and competitive websites, then you are likely the victim of scraping bots.

Anomalous geographical traffic

If a wave of web traffic comes from locations where your customers don’t live or where you don’t offer your service, then you may be under attack. For example, if you operate primarily in the United States and start to see traffic from Iran, North Korea, or Russia, beware.

The best way to beat bad bots is with a bot management solution. As bots grow more advanced, with the ability to mimic human users and solve reCAPTCHAs, machine learning solutions are needed to analyze and predict their behavior. Implementing an AI-based solution that excels at identifying malicious bot activity on mobile applications, websites and APIs will help ensure that you can keep pace with new bot attacks as they emerge, and effectively block them.

Bot management solutions should be:

• Fast: Able to process brute-force and ATO attacks
• Accurate: Low false positives (FP) and false negatives (FN)
• Friction-free: Does not drive away real users
• Mobile-ready: Performs well with mobile apps
• Low risk: Does not collect personally identifiable information (PII)

The Human Defense Platform offers a suite of bot management solutions that protect your websites, mobile applications and application programming interfaces (APIs) from automated attacks. These include Account Takeover Defense, Transaction Abuse Defense, Scraping Defense, Ad Fraud Defense, and Data Contamination Defense. HUMAN leverages more than 400 advanced machine learning algorithms, behavioral analysis, and predictive methods to detect and mitigate automated attacks with exceptional accuracy.

HUMAN’s bot management solutions operate asynchronously to mitigate bad bots at the edge, ensuring low latency and optimizing infrastructure costs. If required, we serve the Human Challenge, a user-friendly verification feature that protects against CAPTCHA-solving bots while maintaining a positive user experience. By stopping bad bots without adding friction, HUMAN’s bot management solutions reduce risk, protect revenue and reputation, and drive operational efficiency.

What type of damage can a bot do?

Bad bots can cause significant issues by executing malicious activities such as stealing sensitive data, conducting fraud, or overwhelming systems with fake traffic. They can also damage a brand’s reputation, inflate advertising costs through fake clicks, and scrape valuable content for unauthorized use.

Can bots be illegal?

Yes, bots can be illegal if they’re used for malicious purposes, such as hacking, data theft, or conducting fraudulent activities like credential stuffing or ad fraud. Additionally, bots that violate terms of service, scrape copyrighted content, or disrupt online services can also be considered illegal, depending on local laws and regulations.

Where do bots come from?

Bots can be created by either developers or cybercriminals using various programming languages and frameworks to automate tasks or perform malicious activities. They’re typically deployed on servers or through cloud services, where they can operate at scale, either as part of a botnet or as standalone agents designed for specific purposes.

What is the most common use of a bot?

The most common use of good bots is in customer service, where they automate interactions with customers through chatbots, providing instant responses to inquiries and troubleshooting issues. Conversely, bad bots are most frequently used for data scraping, credential stuffing, ad fraud, and launching DDoS attacks.

What are bots used for on social media?

On social media, bots are used to automate tasks such as liking, commenting, following, and posting content, often to increase engagement or boost a user’s online presence. While some bots are used for legitimate purposes like customer service, others can be malicious, spreading spam, manipulating trends, or generating fake accounts to influence public opinion.

What is account takeover? | How to detect & stop it

Carding: what it is and how to prevent it

What is scraping? | Protection from web scraping & data scraping

What is bot detection? | How to detect & block bad bots

What is bot mitigation? | 4 types of bots & botnets | How to stop bots