New Zealand botnet crackdown dangerous despite 2007 bots drop

The botnet crackdown in New Zealand is only tip of the iceberg. The majority of people with compromised computers do not even know their computers are being used for criminal activity. They themselves may not be financially affected but their computers are used to steal saleable personal data from others, or simply act as relays for spam and phishing.
 
Bots are operated by organized international cyber-crime groups and remain at the heart of botnets considered one of the most lucrative e-crime business models at the moment.
 
Bots first reach computers in emails that use social engineering and exploit system vulnerabilities. They then get installed silently and operate for long periods until they turn computers into zombies that become part of a larger network. 
 
Dominic Hoskins from Panda Security UK commented:

There is an underground market for renting bots to send spam or install spyware or adware and a zombie spam server will go for as little as ?250

Botnets also flood websites with data to knock them offline. The launch of iPhone, for instance, was exploited by a botnet made up of over 7,500 zombie computers. In effect, users of infected computers were taken to a spoof “official” iPhone page and had their bank details exploited.
 
Bots have evolved over the last year and so the way they are controlled is changing too. Until now, most of them have been controlled through IRC servers, which was useful for controlling isolated computers and allowed attackers to send orders while hiding behind the anonymity of chat servers. Now, bots can be controlled through Web consoles using HTTP, which helps control many computers at the same time, and allows checking if and when computers are online or whether the commands have been executed correctly.
 
Bots can be best prevented by security solutions that rely on proactive technologies but companies are also strongly advised to carry out additional periodic online security audits?.