What is a Botnet?
A botnet is a covert network of compromised computer devices controlled by malicious software known as bots.
Stemming from the legacy of Internet Relay Chat (IRC) bots, these entities are installed on computers through worm or virus infections or by exploiting vulnerabilities in web browsers. Each infected device becomes part of malicious activities, subject to remote manipulation by a master, facilitating spam distribution and DDoS attacks.
A botnet utilises victim devices’ computing power for various malicious purposes, functioning as an automated army, which allows it to operate efficiently. These compromised devices can be hijacked by multiple perpetrators, executing diverse cyber attacks, from rapid website access to vulnerability scans. Botnets represent a combination of hijacked devices, serving as a potent tool for wide-scale scams and cyber disruptions, all without the consent of the device owners.
Common Botnet Infection Methods
- Malicious Email Attachments or Links: Phishing emails with malicious attachments or links are one of the most popular ways to infect botnets. These emails could seem authentic, tricking recipients into opening attachments or clicking on links that infect their devices with malware.
- Drive-by Downloads: Drive-by downloads, in which malware is downloaded onto a device automatically when a user visits a hacked or malicious website, are another way that botnets can infect devices. If the malware finds software flaws on the user’s device, it can make use of those vulnerabilities without the user’s knowledge or consent.
- Exploiting Software Vulnerabilities: Botnets are able to infect devices by taking advantage of flaws in operating systems, firmware, or software, which may occur if devices are not kept up to date with the most recent security updates and fixes, which leaves them open to malware exploitation.
- Social Engineering Attacks: Botnets may use social engineering techniques to fool people into downloading malicious software onto their devices. Fake antivirus alerts, software upgrades, and misleading pop-up windows that encourage users to download and install harmful software are a few examples of this.
- Infected Removable Media: Botnets can propagate through infected detachable media, such as external hard drives or USB devices. When a user links an infected device to their computer, the malware can spread to the computer and potentially infect other devices on the same network.
- Exploiting Weak or Default Passwords: Devices, including routers, Internet of Things (IoT) devices, and network-attached storage (NAS) devices with default or weak passwords, are vulnerable to botnet attacks. These devices can be used as entry points to infect other networked devices once they are compromised.
Common Tasks Carried Out by Botnets
- Spam emails: Large numbers of spam emails supporting phishing scams, malware distribution, and other fraudulent activities can be sent out from infected machines.
- Distributed Denial of Service (DDoS) attacks: A target server or website might be rendered inaccessible to legitimate users by an immense flow of traffic coordinated by botnets from infected devices.
- Data theft: Bots can be designed to take credit card numbers, login passwords, and other sensitive data from compromised devices, as well as financial information.
- Click fraud: Botnets can commit click fraud, wherein they click on web ads fraudulently in order to make money for the botmaster.
- Mining cryptocurrency: Utilising the processing capacity of infected devices to solve challenging mathematical problems and earn virtual currencies like Bitcoin or Monero, some botnets are used to mine cryptocurrency.
Known Botnet Strains
- Emotet: A highly developed and extensively used botnet, Emotet is well-known for its capacity to spread malware payloads, including TrickBot and Ryuk ransomware. It is often disseminated via phishing emails and is well-known for its adaptability and evasion strategies.
- Mirai: Large-scale Distributed Denial of Service (DDoS) attacks using flaws in the Internet of Things (IoT) devices, including routers, IP cameras, and DVRs, brought Mirai recognition in 2016. Some of the most significant DDoS assaults in history, such as the one against Dyn DNS that caused major internet services to go down, were caused by it.
- TrickBot: TrickBot is a multipurpose banking malware that has developed into an advanced botnet that is able to carry out a wide range of nefarious tasks, such as stealing credentials, altering browser settings, and dispersing ransomware like Ryuk. Exploit kits and spam emails are common ways for it to propagate.
- Zeus Gameover: A variation of the Zeus banking trojan is called Zeus Gameover, or Gameover Zeus. It is mainly made to take financial information and banking credentials from devices that have been compromised. It has been a part of extensive financial fraud schemes and has cost people and businesses a great deal of money.
- Necurs: One of the biggest and most persistent botnets, Necurs is renowned for its adaptability and durability. It has engaged in a number of illegal actions, such as the dissemination of malware, spam, and DDoS assaults. Numerous malware families, such as banking trojans, cryptocurrency miners, and ransomware, have been disseminated by Necurs.
How can iZOOlogic help my Company or Organisation?
Find out how iZOOlogic can protect you against Botnet threats with the Financial Malware / Trojan Monitoring solutions.
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