What Is Bot and How Does It Work?

A bot is a software program that is mainly used to automate certain tasks so they could be run without further human instructions. One of the main reasons for using bots is their ability to perform automated tasks much faster than humans.

In this article, we will explain how bots work, their main types, and how good and malicious bots differ from each other.

How do bots work? 

Bots are designed from sets of algorithms that help them in their appointed tasks. From conversing with a human to gathering content from a website – there are numerous types of bots differently made to achieve a wide range of tasks. 

For instance, there are numerous methods of operation by which a chatbot can run. While a rule-based bot will interact with humans by providing predefined options to select from, an intellectually sophisticated bot will use machine learning to learn and look for specific keywords. Such bots may also employ tools for pattern recognition or natural language processing (NLP). 

For obvious reasons, bots do not click on content in a traditional browser and do not operate a mouse. They typically do not access the internet via web browsers as human users do. Instead, bots are software programs that send HTTP requests besides other tasks and usually use a headless browser.

Types of bots

There are many types of bots active on the internet utilizing all sorts of tasks. Some of them are legitimate, while some operate for malicious purposes. Let’s go through the main ones to get a better understanding of how the bots ecosystem works.

Web crawlers 

Web crawlers, also known as web spiders or spider bots, scan content over the internet. These bots help search engines to crawl, catalog, and index web pages in order to provide their services efficiently. Crawlers download HTML, CSS, JavaScript, and images and use them to process the content of the site. Website owners might place a robot.txt file in the root of a server, thus informing bots which pages they can crawl.

Monitoring bots

Site monitoring bots monitor the health of the system, such as loading times. This allows website owners to identify possible issues and improve user experience. 

Scraper bots

Web scraping bots are similar to crawlers, but they are used for reading publicly available data from websites with the objective of extracting specific data points, for example scrape real estate data, and etc. Such data could be used for research purposes, ad verification, brand protection, etc.

Chatbots

As mentioned previously, these bots can simulate human conversations and respond to users with programmed phrases. One of the most famous chatbots was created in 1963, prior to the web, and called Eliza. It pretended to be a psychotherapist and mostly turned users’ statements into questions based on specific keywords. Nowadays, most chatbots use a combination of defined scripts and Machine Learning.

Spam bots

Spam bots are malicious bots that scrape email addresses for the sole purpose of sending unsolicited and unwanted spam emails with nefarious intents. Spammers may also perform even more hostile attacks, such as cracking credentials or phishing.

Download bots

Download bots are used to automate multiple downloads of software applications in order to increase statistics and gain popularity in app stores. 

DoS or DDoS bots

DoS or DDoS bots are designed to take down websites. An overwhelming amount of bots attack and overload a server stopping the service from operating or weakening its security layers. 

What is malicious bot activity?

It is easy to tell the difference between malicious and good bots when we know the ultimate intent. So the goal is to define whether bots’ activity is harmful or not. Another example, some bots are designed to utilize neutral tasks, like colorizing black and white photos on Reddit, while malware bots may be used to gain absolute control over a computer.

For better understanding, this is the most common malicious bot activity:

• Spam content

• DoS (Denial of Service) or DDoS (Distributed Denial of Service) attacks

• Credentials stuffing

• Click fraud

According to research, malicious bots activity grew to its highest ever percentage of 24.1% of all online traffic in 2019. This means that 37.2% of overall traffic was not human. 

How do websites detect bots?

Websites have developed numerous methods and techniques to detect bot traffic and block it. From simple daily encountered CAPTCHAs to complex measures, they all help to reduce the exposure to bots:

• Following the parameters on web analytics can indicate bot traffic on a website:
  A slowdown in loading times
  Odd traffic patterns, especially when it happens not during common peak hours. 
  Suspicious IPs or activity from unusual geo-locations.
  Many requests from a single IP (unlike humans, bots often request all web pages)

• Placing CAPTCHAs on a website’s sign-up or download forms. This challenge-response type of test helps to prevent spam bots. Tip: check this blog post on how do CAPTCHAs work.

• Adding a robot.txt file in the root of the website servers serves as entry rules for bots which pages can be crawled and how frequently.

• Checking browser fingerprinting allows indicating the presence of attributes added by headless browsers.

• Setting a detection tool as an alert to notify of a bot entering a website. 

• Inspecting behavioral inconsistencies, such as repetitive patterns, nonlinear mouse movements, or rapid clicks, can also be a sign of a bot-like behavior.

These and many other anti-bot measures allow websites to spot bots and ultimately block them. If you are interested in how websites recognize suspicious behavior, read our blog article How Websites Block Bots.