← Back to Glossary

What is a Bot?

by Iwan Price-Evans on Security • April 20, 2022

The term 'bot' is short for 'robot'. A bot is a software program that performs repetitive tasks by following a Robotic Process Automation (RPA) script. Bots process instructions to complete tasks that would otherwise have required thousands of hours for a human to complete. Bots can perform tasks in huge volumes quickly and accurately.

Are bots good or bad?

Bots are useful for complex tasks such as analyzing large volumes of data or performing complex calculations. Academic or research organizations use bots for this purpose. They are also used by search engines to 'crawl' the internet collecting information and adding it to the search indexes.

Bots were first created as helpful software applications but are now thought of as harmful. This is because hackers use them for malicious purposes. They are used to distribute viruses or malware, steal data, spy on networks, or perform any number of malicious tasks.

How does a bot work?

A bot can be part of a distributed computing system called a botnet. A botnet is a collection of computing devices that are connected and programmed to perform repetitive tasks.

Bots can be installed on a device and remain dormant until instructed to start working by their controller. Distributed bots communicate with their controller and can also communicate with each other.

Each bot has an RPA script that contains a set of logical instructions which are generally not complex.

Types of bots

Bots can be used to improve user experience, increase sales, or collect legitimate information. Similarly, they can be used for fraud, theft, or ransom.


Chatbots are used as customer service assistants to answer frequently asked questions or to triage support requests. They can improve the efficiency of support teams by reducing the number of requests needing to be handled by humans. 

Spider or crawler bots

Bots that crawl the internet are also referred to as spiders. These are used by search engines to update their indexes as they visit and revisit websites. Crawlers can also be used by hackers to identify vulnerabilities and deliver malicious applications like viruses or malware.

Scraper bots

Scrapers crawl the internet looking for and collecting specific information or 'scraping'. The use of scrapers is a gray area because while they can be used legitimately, they can also be used to plagiarize web content or steal data. Scraping can be used to collect and display relevant information to web visitors or customers. It can also be used to collect publicly available data such as email addresses. Hackers can use them to collect login information or credit card details from unprotected sources.

Shopping bots

In recent years bots have been developed to drive customers through the purchasing process. Shopping bots have been developed to present e-commerce customers with relevant products or offers based on their behaviors. Shopping bots can also be used maliciously to purchase huge volumes of popular products such as sale items.

Monitoring bots

Bots can be used to monitor networks or websites for vulnerabilities. These can also be used to monitor user activity, identifying and alerting specific actions taken by a user. This type of monitoring can be legitimate but can also be restricted by privacy laws.

Transaction bots

This type of bot assists commercial transactions such as online purchases. They are used to authenticate purchases during a checkout process verifying a person's identity and refusing the purchase if the card being used is stolen. 


Spambots are usually part of a botnet and when triggered by their controller can send thousands or millions of spam messages. These can be emails, social media posts, or chat messages. They can be sent by criminals aiming to deliver viruses or phishing emails. They can also send unsolicited sales promotions.

Credential stuffer bots

This type of bot uses stolen login credentials or suspected login credentials to attempt to take over legitimate user accounts. It will automatically try to log in to an account using high volumes of credentials attempting to gain access. The credentials used by these bots have often been stolen through data breaches and may have been collected by crawler bots.

DDoS bots

Similar to spambots, denial of service (DDoS) bots are part of a botnet. This type of bot will work in conjunction with other bots to send massive amounts of web traffic to a website. The attacker's intention is to overload the website and stop it from working. This type of attack is often used to hold a company to ransom and is a common technique used by hackers.

Click bots

Click bots are designed to pretend to be humans, clicking web adverts to increase the appearance of ad engagement. This can be used to fake large volumes of pay-per-click views or social media engagements which generates income. These bots can be used to fake anything that relies on clicks to generate income.