Would-be iPhone owners are being targeted by a 7,500-strong zombie botnet, security experts have warned.

PandaLabs said that buying an iPhone online could cost surfers a lot more than the advertised price if their computers become infected by the Aifone.A Trojan. 

Users of an infected PC who try to buy an iPhone online will be taken to a false page that appears to be the official iPhone page. If the user tries to buy the phone from the spoof page, they will be giving their bank details to cyber-criminals.

PandaLabs said that it has uncovered a special tool used by cyber-criminals to control the botnet.

Cyber-crooks can use the tool to display pop-ups and banners with advertising about the iPhone aimed at enticing infected users to visit the spoofed web page.

"This is one of the most sophisticated attacks we have seen targeting a user community, in this case iPhone users," said Luis Corrons, technical director at PandaLabs.

"It is a complex and dangerous attack that combines elements of malware (the Trojan), phishing (the spoofed web page) and even adware (pop-ups, modification of search results etc)."