With the technology advancing every year, the threat of abusing or misusing the same technology is rising as well. For example, the Internet saw monumental growth over this decade, but at the same time, the number of online threats has reached its peak with an attack getting discovered every now and then.
The botnet is such a threat, which is caused by misusing handy technologies for executing malicious tasks. But wait, what is a botnet? Let’s read in detail.
What is a Botnet?
A botnet is a network of bots running on a set of devices connected through the Internet. It’s capable of performing a multitude of high-risk attacks like DDoS (Distributed Denial-of-Service), sending spam, and stealing data. It also allows an attacker to access the device directly, thus making it quite dangerous.
The word “botnet” is a mix of two words — robot and network. A bot or robot in a botnet is a device owned or infected by an attacker, which is connected to more such attacker-controlled devices, thus creating a net or network.
That means a botnet is a big network of malware-infected devices (like a set of computers connected to a LAN or Wi-Fi) combinedly working for a malicious actor — cybercriminal or hacker — to accomplish one of his illegal plans.
How do Botnets Work?
A botnet malware looks for vulnerable devices across the web with the motive of infecting and getting control of as many devices as possible. Then, it uses part of their computing resources for running its own tasks in a hidden manner.
For example, an ad-fraud botnet looks for computers and mobile devices, infects them, and then control them to create its network. Then, it controls the devices’ browsers to divert fraudulent traffic to its target advertisements and websites. Of course, it only controls part resources to stay hidden during its work.
However, the fraction of resources on a single system won’t suffice the needs of the ad-fraud campaign by the attackers. That’s why a botnet combines millions of computing devices to create a huge amount of fake traffic for its ad-fraud campaign while using just the required resources for avoiding detection.
Examples of Botnet Attacks
Let’s get to know a few historic botnet attacks to understand the characteristics (including their targeted systems) and motives behind botnet attacks.
Zeus, which was first known in 2007, was one of the most popular malware in history. It used a trojan horse to infect vulnerable systems and collect crucial information like bank account credentials and other financial data.
Damballa, a cybersecurity vendor, estimated in 2009 that Zeus had infected around 3.6 million devices. A year later, the FBI identified a group of cyber criminals and arrested more than 100 people in the U.S. and Europe.
Srizbi, first discovered in 2007, was the largest botnet of its time. It was known to be responsible for sending a humongous amount of spam emails — 60 million emails a day, which was roughly half of all spam emails sent at that time.
This botnet used a trojan to infect computing devices, which were then used to send spam emails. It’s estimated that Srizbi had infected 450,000 devices.
Methbot, first revealed in 2016 by White Ops — a cybersecurity organization, was an ad-fraud malware. It used to generate $3 to $5 million daily in fraudulent ad revenue by making fake clicks and views on targeted ads and videos.
It was unique since it didn’t infect random vulnerable devices but targeted at data centers in the Netherlands and the U.S. Its network of infected devices used to automate fake clicks and mouse movements as well as forge logins of social media accounts to avoid the traditional ad-fraud detection techniques.
How to Defend against Botnets?
“Prevention is better than cure” — this is the simple principle you must follow to protect yourself from botnet attacks. Why? A botnet usually finds and targets vulnerable computers or smartphones. Also, when your device gets infected, you won’t know or get security alerts since the malware maintains its cover.
That said, you’ll never see it coming. That’s why you must assume now that your device may have been infected and take proper actions to clean your device. Of course, these actions will also protect your device from getting infected (if not already) in the future. Let’s get to know the defense techniques below.
- Install a good security system – You must install reputed anti-virus and anti-malware along with firewall (or preferably an Internet security suite). It auto-scans for malware and viruses in your system to protect it against infections and quarantines them (if found) to secure your system.
- Update your apps and system – A botnet malware usually finds vulnerable systems, so it’s better to patch the vulnerabilities in your apps or system using their latest updates. That said, you must update them both regularly to secure your devices against such botnet or malware attacks.
- Avoid phishing or spam emails – Do you know the most common attack vector used by malware creators? It’s your inbox. You shall simply avoid opening any unknown or suspicious emails, clicking given links inside them, or downloading any attachments from unknown emails.
- Avoid pirated media or software – Everyone warns about pirated stuff for the right reason. They may contain malware or virus (generally the new and undetectable ones) within themselves — even within audio or video files. That’s why you shall avoid downloading pirated materials.
- Avoid unknown or suspicious sites – There are dozens of online websites that lure you into opening them or downloading a game or software, say a latest online game built around the theme of “Game of Thrones”. At the end of the day, their only goal is to install malware into your system.
In short, attackers usually look for easy targets for creating botnets. That’s why you must always keep your defenses up to avoid showing up in their radars. Also, these defensive techniques protect against other forms of online threats.
That is all about botnet, its malware, and how to protect against botnet attacks. Did you understand? Please leave your feedback by writing a comment below.