By definition, a botnet is a network of computers infected by malicious software. The botnet master can control it remotely without the computer owners’ knowledge. Its main aim is to use zombie PCs to send tons of spam, carry viruses and steal users’ bank details through phishing.
Although many botnets have already been dismantled by the relevant authorities, this has had only a minor impact on the phenomenon. The reason is that no joint, concrete action has yet been taken by subscribers and ISPs. Security software publishers have just released some figures on botnets. In 2010, the flow of spam circulating around the world was closely linked to botnet activity. The Rustock botnet was the best-known and most powerful at the time. The spam rate recorded by computer security editors during his reign was 92%. What’s more, 88.2% of spam worldwide was sent via botnets in 2010. 3.5 to 5.4 million computers were controlled by master botnets over the same period. Rustock was the biggest botnet of 2010. It has over a million zombie computers and sends over 44 billion spam messages worldwide every day. In addition, the number of malware strains recorded by IT security publishers was close to 340,000 during the same year. The hackers had no trouble developing several versions of malicious code from existing polymorphic software on the market. As a result, increased Internet speeds benefit not only users, but also malicious parties. 14 million pieces of malware were identified in 2010, or 60,000 every day.
Faced with attacks by botnet masters, several countries decided to take significant action in 2010. In the USA, a best practice guide aimed primarily at ISPs has been drawn up, with the aim of reducing the activities of cyber-criminals and making Internet users safer. This action was also followed by a number of countries, including Germany and other European countries. The aim is for ISPs to be able to detect botnet attacks and inform affected users in good time. In Australia, Internet service providers have decided to isolate users likely to endanger the security of others. In Japan, Internet service providers have set up a centralized platform to combat botnets more effectively. In all these initiatives, the costs will be shared between all the players.