Botnets are opportunistic attack behaviors in which a device makes money for its bot herder. The ways in which an infected device can be used to produce value can range from mining bitcoins to sending spam emails to producing fake ad clicks. To turn a profit, the bot herder utilizes devices, their network connections and, most of all, the unsullied reputation of their assigned IP addresses.
How does a botnet work?
A botnet is a network of infected devices that are controlled by a single attacker. These devices, called "bots" or "zombies," are compromised through various means, such as phishing emails, drive-by downloads, or exploiting vulnerabilities in software or websites. Once infected, the bot replicate itself and becomes part of the botnet that can be commanded by the attacker to perform various malicious tasks. Botnets serve as a primary tool for launching DDoS attacks.
A botnet lifecycle consists of three main stages:
- Infection: The attacker spreads malware to acquire new bots. This can be done through phishing emails, drive-by downloads, or exploiting vulnerabilities in software or websites.
- Control: The attacker gains control over the infected devices, typically through a command-and-control (C&C) server. This server allows the attacker to issue commands to the bots, coordinate their activities, and update the malware.
- Exploitation: The attacker uses the botnet to carry out malicious activities, such as launching DDoS attacks, stealing data, spreading malware, or conducting spam campaigns.
List of notable botnets
Botnets have become increasingly sophisticated and harmful in recent years, posing a significant threat to businesses and individuals alike. Here's an overview of some notable botnets active since 2018 and their impact on enterprises:
- Emotet (2018-present):
Emotet, considered as the world's most dangerous malware botnet, is a highly adaptable and resilient botnet that primarily spreads through spam emails containing malicious attachments or links. Once infected, Emotet can steal sensitive data, install additional malware, and distribute spam emails. Despite Europol's effort to take the botnet down in January 2021, it resurfaced later in the year. Though it is still active today, Microsoft's updates significantly lowered its impact.
- TrickBot (2016-present):
TrickBot is a modular botnet that can be customized to carry out various malicious activities. It often disguises itself as legitimate software or attachments to trick users into opening it. Once installed, TrickBot can steal personal information, spread ransomware, and launch DDoS attacks. TrickBot has targeted a wide range of industries, including healthcare, financial services, and retail. Its modular design makes it highly versatile and adaptable, enabling it to carry out a wide variety of attacks.
- BazarLoader (2018-present):
BazarLoader is a sophisticated botnet that primarily targets Windows systems. It typically operates in the background, silently collecting information about the infected device and its network environment. This information is then used to deliver other types of malware, such as ransomware, trojans, and cryptocurrency miners.
BazarLoader has been linked to a number of high-profile cyberattacks, including the SolarWinds supply chain attack. Its ability to gather detailed information about infected systems makes it a valuable tool for attackers planning more sophisticated attacks.
- Gandcrab (2018-present):
Gandcrab is a ransomware-as-a-service (RaaS) botnet that allows cybercriminals to rent access to a large network of infected machines. Once infected, Gandcrab encrypts the victim's files and demands a ransom payment in exchange for the decryption key. Gandcrab has evolved over time, becoming more sophisticated and difficult to detect.
Gandcrab has targeted a wide range of industries, causing significant disruption and financial losses for businesses. Its RaaS model has made it even more prevalent, as it allows cybercriminals with limited technical expertise to launch ransomware attacks.
- Pythor (2021-present):
Pythor is a relatively new botnet that targets IoT devices, particularly security cameras and routers. It can exploit vulnerabilities in these devices to gain control over them and use them to launch DDoS attacks, spread malware, or collect sensitive data.
Pythor's focus on IoT devices poses a significant threat to businesses that rely on these devices for security and monitoring. Its ability to launch DDoS attacks can disrupt critical business operations, and its ability to steal sensitive data can compromise corporate networks.
As botnets continue to evolve and pose a sophisticated threat to global cybersecurity, staying ahead requires vigilance, advanced security technologies, and strategic planning. Vectra AI offers comprehensive solutions to detect, mitigate, and prevent botnet threats, safeguarding your organization's network and digital assets. Contact us to learn how we can help you build a resilient defense against botnet attacks and enhance your cybersecurity posture.