Fewer than five zombie networks could be responsible for the majority of worldwide phishing, according to new research. The research, undertaken by CipherTrust, demonstrates how bot networks are increasingly used to distribute unwanted spam and phishing attacks.

"We've had a great deal of concern about loss of productivity as a result of phishing," said Dmitri Alpervitch, research engineer at CipherTrust. "By analysing phishing trends we realised that most of them are coming from a very limited number of IPs," he said.

The survey also revealed that attacks are becoming progressively more targeted. Citibank suffers the most, with its brand accounting for nearly 50 percent of all phishing attacks. "They are picking the most well known companies for most effective results. There's also an unexpected level of sophistication. For example, Lloyds-TSB directed attacks are confined to Europe," Alpervitch said.

Online bank Egg recently downplayed the effect phishing has on the industry. But speaking at the Sc conference, Andrew Beard, information security advisory director at PricewaterhouseCoopers, seems to disagree. "There's a lot of confidence in the industry regarding security but it's misplaced. If companies are confident, then how come most have had a security breach?" Beard said.

Additionally the study highlights incidence of phishing attacks and production of zombie networks are directly related to bandwidth. More than 32 percent of zombies are based in the US, whereas the Republic of Korea accounts for 16 percent.

Despite this CipherTrust are keen to point out that phishing perhaps isn't as prevalent as many believe. "Attacks are becoming more highly developed, but our study revealed that phishing accounts for less than one percent of all emails. It's actually a very low volume," Alpervitch said.