New Delhi: ZeroAccess, which is one of the largest known botnets in existence, has infected more than 1.9 million computers globally on a given day in August this year with India having the third highest infection rate after the US and Japan, cyber security firm Symantec has said.
Cyber criminals distribute malicious software or malware that can turn a computer into a bot, also known as a zombie or robot, which makes the computer perform automated tasks over the Internet, without one`s knowledge.
Criminals typically use bots to infect large numbers of computers. These computers form a network, or a botnet. They are used to send spam email messages, spread viruses, attack computers and servers and commit other kinds of frauds.
ZeroAccess is a sophisticated and resilient botnet, which has been active since 2011, with an upwards of 1.9 million infected computers on a given day as observed in August 2013, Symantec said.
"While 35 per cent of the infections were observed in the US, India had the third highest infection rate globally, just behind US and Japan. Nearly six per cent of ZeroAccess infections were observed in India, it added.
Symantec takes the first step in successfully combating the ZeroAccess botnet by sinkholing more than half a million bots, thus making a serious dent to the number of bots under the control of cyber criminals, the firm said.
The company is working with ISPs and CERTs worldwide to share information and help get ZeroAccess bot infected computers cleaned up, it added.
"ZeroAccess leverages click-fraud and Bitcoin mining to carry out two revenue generating activities, potentially earning tens of millions of US dollars per year in the process," Symantec said.
Click fraud Trojan downloads online ads onto the infected computer and generates artificial clicks on the ads as if they were generated by legitimate users, it added.
Bitcoins is a type of digital currency and this holds a number of attractions for cybercriminals. The way each bitcoin comes into existence is based on the carrying out mathematical operations known as `mining` on computing hardware, which has direct value to botmaster and cost to the unsuspecting victims.