For businesses to maintain an effective cyber defence, the ability to prevent, detect and stop smart botnets in real-time is now an important consideration.

What Is A Botnet?

A botnet is a term for multiple malicious mini-programs working together to take over large numbers of computers and digital devices for different purposes e.g. stealing data and / or launching attacks, or in the case of DDoS attacks, shutting down servers (and the websites on them) by bombarding them with requests (a flood).  Botnets also sap electricity and computing power as they work.

How Big Is The Problem?

According to DDoS protection provider Link11, DDoS attacks (launched using botnets) on e-commerce providers showed an increase of more than 70% on Black Friday compared with other days in November this year, and Cyber Monday attacks showed a massive increase of 109% compared with the November average. Botnets have also shown a move towards the Internet of Things (IoT).

Last year saw a huge growth in the use of botnets.  For example, Spamhaus figures showed that the number of command and control (C&C) servers used for managing IoT botnets more than doubled, going from 393 in 2016 to 943 in 2017.

The increase in the use of botnets has been driven by factors such as the availability to cyber criminals of very cheap and easy to operate rent-a-botnet services booter or stresser botnet services, and the proliferation of IoT device with sub-standard security that can be used in attacks. Cyber criminals also use various amplification techniques to increase the impact of their attacks.

Characteristics Of Botnets

The characteristics of botnets and how they are made can provide the key to detecting them and preventing them. For example:

• Some have a long ‘dwell time’ (the time the malicious program sits on a device before it’s activated), and they need to communicate to work. Communication often involves the use of command and control servers. Disconnecting communications between bots and their botnet command and control servers has, therefore, been a way of stopping them.  New smart bots, which create peer-to-peer networks, can be more difficult to stop.
• Botnets use processing power.  If suspicious processes that take up a lot of memory are spotted, and/or if devices appear to slow down, this can be an indicator that the device has been compromised and a botnet is awake and active.

Turned To Crypto-Mining

A recent security bulletin from Kaspersky Labs states that botnets are now increasingly being used to distribute illicit crypto-mining software, and that the number of unique users attacked by crypto-miners grew significantly in the first three months of 2018. The malware used for mining is designed to secretly reallocate an infected machine’s processing power to mine cryptocurrencies, with all the proceeds going to the attacker.

What Does This Mean For Your Business?

With cyber-crime, prevention is better than cure, and being able to detect signs of attacks early is vitally important. Security commentators suggest a focus on security measures that prevent initial infection and lock-down unnecessary trust permissions. Businesses may also benefit from using security technologies that can detect, alert or block botnet activity in real-time, and by continually analysing network traffic and local system logs.

Inspecting devices and checking for any suspicious processes that appear to be taking up taking up a lot of memory may also be a way to detect botnets that have already slipped through the net and are active.