Semalt: Botnets And How They Work
Frank Abagnale, the Semalt Customer Success Manager, explains that a botnet is a series of malware-infected computers which form a network that a user can control remotely. They are called "bots" since they are under the direct influence of the person infecting them. Botnets vary in size, but the bigger it is, the more efficient it becomes.
Botnets in Details
If you are confident that the computer you use is a part of a botnet, there is a high chance that it was "recruited" after it got infected by malware. After installing itself in the system, it either contacts the remote server or any nearby bots within the same network. The one controlling the botnet then sends out instructions as to what the bots should do.
Essentially, when a computer is said to be part of a botnet, it means that someone has remote control over it. It becomes susceptible to other malware types such as keyloggers, which collect financial information and activity and relay it back to the remote server. Botnet developers decide what to do with it. They can stall its functions, make it download other botnets, or assist others in task implementation. A few vulnerabilities in the computer such as outdated software, insecure Java browser plugins, or downloading pirated software, are easy target points for botnet attacks.
Most of the malware created these days is usually for profit. Therefore, some of the botnet creators only want to amass as many bots as they can to rent out to the highest bidder. In fact, they can be used in many various ways.
One of them is the distributed denial of service attacks (DDoS). Hundreds of computers send out requests to a website at the same time with the intention of overloading it. Consequently, the website crashes and becomes unavailable or unreachable by the people in need of it.
Botnets have some processing power which can be used to send out spam emails. Also, it can load websites in the background and send fake clicks to a site that the controller wishes to advertise and improve on its SEO campaign. It is also efficient in mining Bitcoins, which they can later sell for cash.
Also, hackers can use botnets to distribute malware. Once it gains entry into the computer, it downloads and installs other malware such as keyloggers, adware, or ransomware.
How Botnets Can Be Controlled
The most basic way to manage a botnet is if each of the individual computers communicates with the remote server directly. Alternatively, some developers create an internet relay chat (IRC) and host it on a different server where the botnet can await instructions. One only needs to monitor which servers the botnets mostly connect to and then take them down.
Other botnets use the peer-to-peer way by interacting with the nearest "bots," which then relay information to the next in a continuous process. It makes it impossible to identify the data source point. The only way to disrupt the botnet's efficiency is to issue false commands, or isolation.
Finally, the TOR network is becoming a popular communication medium for botnets. It is hard to foil a botnet that is anonymous in the Tor network. Without any slip-ups by the person running the botnet, tracking it and bringing it down is quite difficult.