What is a bot and how does it work?

A bot is an automated software program that independently performs digital tasks and, for example, crawls websites, answers chat messages, compares prices or automates login attempts. Bots can work on a rules-based basis or use artificial intelligence. This means their areas of application range from search engine crawlers, chatbots and AI agents to spam bots, phishing bots and botnets.

What is a bot?

The term ‘bot’ comes from the word ‘robot’. Much like mechanical robots, internet bots are programmed to carry out specific, repetitive tasks. They follow clearly defined commands in the form of algorithms and scripts, allowing them to complete these tasks much faster than a human could. Bots are therefore computer programs that operate independently and automatically, without requiring ongoing human involvement or supervision.

The first known internet bot was the World Wide Web Wanderer, which began measuring the growth of the internet in 1993 and stored the data it collected in an index known as Wandex. Today, bots have a much wider range of uses. They support customer service as chatbots, operate on social networks as social bots, analyse websites as web crawlers and can also be used in botnets to carry out spam and phishing attacks.

How does a bot work?

The easiest way to understand how bots work is to compare them with physical robots. Unlike robots, they are not made up of material machine parts such as screws, threads, plastic and wires, but of code. The code contains the necessary commands and instructions that tell the bot how it should communicate actively or reactively with human users, systems or other bots.

Bots can range from very simple programs to sophisticated systems that use complex code and artificial intelligence. On social networks, advanced bots can sometimes be difficult to distinguish from human users. Today, even people without programming expertise can create bots using the many tools and interfaces available online, from basic automated programs to more complex applications.

Based on the algorithms defined in the code, bots can perform a range of simple or complex tasks. Communication usually takes place via internet-based platforms and services, such as instant messaging (IM) or Internet Relay Chat (IRC).

What functions can a bot have?

Bots can perform a wide range of functions depending on how and where they are used online. Some of the most common include:

• Supporting communication services on instant messaging platforms such as Facebook, X and WhatsApp.
• Automatically collecting data through web scraping by searching, analysing and indexing information on websites using keywords, pattern matching or hashtags.
• Simulating and automating predefined communication based on specific keywords, algorithms or hashtags, for example in chats, on websites or in customer service.
• Connecting to other applications and bots through interfaces to perform additional functions, such as collecting and displaying data from weather or traffic apps.
• Providing automated services such as translations, personalised advertising or order processing.
• Performing gaming functions, such as playing chess.
• Forming botnets that use networks of computers to carry out data theft, scams and DDoS attacks.

What is a bot made up of? How bot architecture works

A bot essentially consists of three main components:

1. Application or workflow logic: This is the executable, machine-readable code written by programmers to define the bot’s functions, tasks and processes.
2. Database: The database stores the data and information the program needs to perform its tasks. It can also be continuously expanded, as is the case with search engine bots such as web crawlers.
3. APIs: APIs (Application Programming Interfaces) allow bots to access functions and data from other applications without programmers having to develop these features from scratch. These interfaces integrate external software commands into the bot’s code and extend its functionality.

Rule-based and self-learning AI bots

Simple bots use rule-based ‘if-then-else’ logic to carry out clearly defined, pre-programmed commands and tasks. Modern bots can also use artificial intelligence to adapt over time, expand the data available to them and learn new functions and terms. Bots can therefore be distinguished not only by their area of use, but also by their technical basis.

Rule-based bots follow fixed decision trees, keywords or ‘if-then-else’ rules. Self-learning, AI-powered bots, by contrast, use artificial intelligence to analyse inputs more flexibly and generate responses dynamically. One increasingly important type is the AI agent. AI agents can process natural-language queries, take context into account and, depending on the system, retrieve information from connected tools, databases or APIs.

Based on their main functions, rule-based and self-learning bots can be divided into several groups:

1. Entertainment bots
2. Commercial bots
3. Service bots
4. News bots
5. Malware bots

What types of benign bots are there?

Bots can be used in a wide range of areas on the internet and are all similar in that they provide a service that can be used for both legal and illegal purposes. One of the most important types of bot are chatbots. Simple, rule-based chatbots follow fixed decision trees, keywords or predefined response patterns. They are particularly suitable for standardised requests such as FAQs, appointment bookings or simple support processes. However, they quickly reach their limits when it comes to more complex issues.

Modern LLM-based chatbots use large language models to understand natural-language queries, consider the context of a conversation and generate responses dynamically. This makes them useful not only for customer service, but also for lead generation, sales, internal knowledge searches and the initial assessment of support requests. Combined with live chat support, they can respond to queries around the clock and transfer conversations to human staff when necessary.

If LLM-based chatbots are additionally connected to tools, databases, APIs, memory functions or workflows, conversational AI agents or AI chatbots can emerge from them. Such systems not only answer questions, but depending on the connection can also retrieve information, prepare tasks or carry out individual actions. This sets them apart from classic chatbots, which usually only react to inputs. One example of a ready-to-use AI assistant is the IONOS AI Chat Assistant. It can help businesses collect and analyse customer feedback, identify trends and use these insights to uncover potential areas for improvement.

Other common benign bots (often referred to as ‘good bots’) are:

• Social bots: Umbrella term for all bots that operate on social media and take over automated tasks in the areas of help, FAQs, direct messaging, commenting on posts, or likes, shares, retweets and following.
• Web crawlers: These bots collect and evaluate data and information from websites in order to extend the functionality of search engines and comparison portals, register and index new web content, create links and optimise search queries.
• Gaming bots: These are bots that appear in video games as artificial fellow players (NPCs).
• Shop bots: Bots that compare prices in online shops and look for the cheapest offers or select the most popular shopping sites for users.
• Monitoring bots: They monitor the status of a website or a system.

What malware bots are there and how do they work?

Although bots have many positive functions and numerous services such as search engines, instant messaging or comparison portals would be unthinkable without them, bots have a largely bad reputation because of malware and hacker attacks. This is because many types of bots are developed specifically for illegal and harmful purposes.

The following types belong to malware or malicious bots:

• Propaganda bots or manipulative bots: Social bots that simulate user profiles, influence digital opinion formation and spread political statements, fake news and conspiracy theories, or react to comments and posts based on keywords.
• Scam/phishing bots: These bots steal data using pseudo-links, fake emails and fake websites.
• Keylogging bots: Bots that log message traffic or record, store and forward all activities on a PC.
• File-sharing bots: Bots that respond to targeted search queries and offer users a link to the desired search term. When this link is clicked, the bot can infect the PC used by the person.
• Spam bots: They send large quantities of spam emails and use the address books and contacts of unsuspecting users to deliberately expand their spam radius.
• Zombie bots: So-called zombie bots are computers that have been infected with malware by bots or made part of a botnet and provide computing power for large botnet attacks. Compromised PCs are often not easily recognisable as part of a botnet.
• Botnet: Refers to the entirety of infected PCs that are linked together into a network and serve, for example, as a basis for DDoS attacks.

What types of attacks can botnets carry out?

Botnets can be used for a range of illegal activities, including:

• Data and identity theft through scraping, phishing and keylogging to obtain sensitive information such as passwords, bank details and addresses.
• Distributed denial-of-service attacks (DDoS), in which large volumes of traffic are used to overload and potentially paralyse servers.
• Backdoor attacks, which exploit vulnerabilities in a computer’s security system to infect it with malware.
• Spam distribution and traffic redirection, in which compromised devices are used to relay unwanted messages or redirect data packets.

Five of the most common large-scale bot attacks are:

• DDoS attacks: Deliberately overwhelming servers with large volumes of traffic.
• Spam and traffic monitoring: Overloading email servers, distributing spam or intercepting large amounts of data.
• Denial-of-inventory attacks: Reserving products in online shops so that they appear to be unavailable to genuine customers.
• Scraping attacks: Automatically collecting data for unauthorised use or resale.
• Credential stuffing attacks: Using stolen login details to carry out automated login attempts across a large number of accounts.

How can businesses use bots safely and effectively?

If you work in online marketing, benign bots can help you streamline and automate routine tasks. At the same time, bot management should form an essential part of your company’s cyber security strategy. It helps you identify malicious bots and protect your website or online shop from attacks while continuing to allow access to legitimate bots.