Botnet Detection: A Comprehensive Guide

Originally written at Anura

Updated on: October 12, 2023

Cybercriminals, fraudsters, and scam artists use a wide variety of tools to turn an illicit profit from their victims. One of the most common tools that corporations face is the dreaded botnet attack.

About Bots, Botnets, and Zombie Bots

What Is a Bot?

The word "bot" is a short for “robot." In the realm of cybercrime, a bot refers to an automated software program intended to perform tasks. Bots can serve either malicious or harmless purposes based on their intended functions. Typically, they are programmed to handle repetitive, mundane, and time-consuming tasks that individuals might find tedious to undertake themselves, such as responding to simple inquiries, automatically updating data dashboards, or scanning internet websites to index them for search engines.

What Is a Zombie Bot?

A zombie bot, in the realm of cybersecurity, is a specific breed of malicious bot that effectively commandeers computers and other connected devices, turning them into puppets manipulated remotely by a hacker. This transformation of innocent machines into "zombies" grants unauthorized control to the hacker, allowing them to orchestrate various actions without the device owners' awareness. Zombie bots are a fundamental component in the creation and operation of a botnet, a network of these compromised devices under the hacker's command. The aggregation of these devices into a botnet provides the hacker with a potent tool for executing large-scale cyberattacks, which can encompass a wide range of malevolent activities, from distributed denial-of-service (DDoS) attacks to spreading malware and conducting data breaches.

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What Is a Botnet?

A botnet is essentially a sizable network of compromised computers, referred to as zombie bots, that have been infiltrated and are under the control of malicious hackers. These hackers can remotely manipulate these computers for various illicit purposes without the knowledge or consent of the device owners. When the botnet reaches a substantial size, the hackers can manage and direct its activities through a specialized tool known as the command-and-control servers. These servers use established internet communication protocols like Internet Relay Chat (IRC) and peer-to-peer (P2P) networks to relay instructions and data to the infected devices within the botnet.

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Methods for Building a Botnet

Now, let's delve into the techniques employed by hackers, often referred to as botmasters or bot herders, to construct botnets. Regrettably, there exist numerous avenues through which cybercriminals can create and proliferate their zombie bots, leading to the formation of extensive botnets.

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Mobile Malware Strategy:

One approach involves the creation of a budget-friendly mobile application using a freely available software development kit (SDK), which is then uploaded to an online app store. Concealed within the download of this seemingly innocuous mobile app is a snippet of malicious code. This code operates covertly, generating a zombie bot on any device that downloads the app. This method is a prevalent tactic within mobile click fraud schemes.

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Social Engineering Attacks:

Hackers may disseminate zombie bots via nefarious links posted on social media platforms, dubious websites, or even online advertisements. An unsuspecting visitor to a compromised website or a user scrolling through social media might inadvertently click on such a link.

Subsequently, their device unwittingly downloads a program that transforms it into a zombie bot or another variant of malware. Cybercriminals invest considerable effort in crafting persuasive online messages to deceive individuals into clicking on these malicious links. Alternatively, they might replicate the appearance of an online advertisement from a reputable company and create a counterfeit version that employs a malicious link to install a hacker bot.

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Phishing Attacks:

Email remains a prominent conduit for malware distribution, including the malware instrumental in installing zombie bots. Phishing, a prevalent technique, involves incorporating malware-laden links within emails to deceive recipients.

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Various red flags can indicate a phishing email with malware, including:

·????? Urgent language coercing immediate action

·????? Threats within the email such as overdue payments or account billing warnings

·????? unsolicited communications from unknown sources

·????? ?unusual behavior or language in emails purportedly from familiar contacts.

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Phishers often strive to imitate people known to the recipient to enhance the effectiveness of their deceptive tactics.

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Types of Botnet Attacks

What can cybercriminals and fraudsters achieve with the vast botnets they create? The potential applications of compromised, internet-connected devices are extensive. Those in control, often called botmasters, can employ these botnets to carry out diverse cyberattacks and facilitate fraudulent schemes, all while covering their tracks.

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Common applications of botnets include:

?1.???? DDoS Attacks:

A distributed denial of service (DDoS) attack is one of a botnet's most widespread uses. In this scenario, a botmaster utilizes their extensive network of zombie bots to inundate a targeted network or system, rendering it incapable of functioning normally. The specifics of the attack can vary, ranging from brute force tactics, bombarding the network or a specific device with countless pings, to exploiting specific flaws in a system's handshake protocols to amplify the delay if their botnet isn't exceptionally large. Regardless of the approach, the botnet overwhelms the system or network, disrupting the organization's operations.

?2.???? Click Fraud:

Zombie botnets are frequently utilized in click fraud schemes. Here, a swarm of zombie bots operates discreetly, clicking on ads to artificially inflate clicks for pay-per-click (PPC) campaigns. Advertisers and merchants overseeing PPC campaigns observe increased click counts, believing that the affiliate responsible has effectively generated interest in the ad or website link, and thus ends up paying the fraudster money. In recent times, human fraud farms have emerged, either supplementing or replacing click fraud bot schemes. With actual humans conducting fraudulent clicks, human fraud farms are considerably harder to detect and counter using ad fraud and botnet detection tools.

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3.???? Content Scraping:

Bot programs are employed to pilfer information from websites in this scenario. The "scraped" content can be utilized in various ways, including undercutting prices on goods and services, replicating content and design elements entirely (often seen in the creation of spoofed websites imitating legitimate ones), and undermining a website's SEO by replicating content on another URL, creating the illusion of duplicate content.

4.???? Email Spam:

Email phishing attacks frequently involve sending many messages to individuals in different companies or departments within a company, aiming for at least one person to click on a malicious link. However, a fraudster might lack the email addresses of their desired targets. To reach unknown targets, they employ bots and botnets to automate the spam and phishing emails sent to every email address in the contacts list of an infected device. As recipients click on the malware link and become infected with a zombie bot, their contacts receive a message, creating a chain that expands the fraudster's network of compromised devices. Alternatively, fraudsters can utilize simpler bots to spam extensive mailing lists with the contact information collected by third parties without consent.

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5.???? Financial Data Breach:

Another prevalent use of botnets is to facilitate breaches of financial institutions. These breaches can lead to compromised banking access credentials, credit card details, customer contact information, and even personally identifiable information (PII), which can be exploited in identity theft schemes. Cybercriminals either use the stolen data or sell it on the "dark web" for profit, with credit card details sometimes priced as low as $12-$20 USD.

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Finding the Right Botnet Detection?

Regardless of?how?a botnet attack is targeting your organization, the solution may very well be the same. Early botnet detection can be crucial for effectively responding to (and stopping) the attack.

A bot that attacks your website isn’t typically going to behave exactly like a normal human visitor. For example, it will often fail to log on to various services, quickly load up items into then promptly abandon carts, exhibit irregular viewing behavior (being on-page for less than a second), and do weird things to your online forms. Additionally, botnet traffic tends to hit all at once (though more sophisticated fraudsters may stagger their zombie bots’ efforts).

However, these warning signs aren’t always easy to spot manually—and manual checks take precious time to complete. To protect yourself from botnet attacks, you need to know who is visiting your site?in real time. You need to analyze where incoming traffic is coming from and what it is doing. You need to be able to identify bots before the issue gets out of hand. You will?require?an ad fraud solution.?

A professional, high-quality ad fraud solution such as?Anura, will monitor your traffic constantly to determine which visitors are real and which ones aren’t. Once identified, you’ll get a notification of the invalid traffic that came from bots (and other sources of fraud)—complete with a report of the data showing?why?the activity was tagged as fraud. This allows you to clear out the bad while keeping the good.

Your business is free to go back to doing what you do best, without having to worry about where the next attack is coming from. In the modern age, no one is too big or too small to be targeted by fraudsters taking the easy road to riches, but you can control how hard it is to hit you. Don’t be an easy target,?demand a free trial today.