A security firm has warned that malware writers are attempting to fool mobile phone users with bogus text messages.

McAfee, which calls the process smishing (SMS phishing), has reported that users are receiving SMS messages with the following text: 

'We're confirming you've signed up for our dating service. You will be charged $2/day unless you cancel your order: [web address removed].

"This phenomenon is yet another indicator that cellphones and mobile devices are becoming increasingly used by perpetrators of malware, viruses and scams," David Rayhawk, mobile threat researcher at McAfee, wrote on the company's Avert Labs blog. 

Rayhawk warned that unwitting users fearful of incurring premium rate phone charges may visit the website listed in the message.

On visiting the site, they are asked to download a program that purports to be a free antivirus application but is actually a Trojan horse that turns their computer into a zombie PC that can be controlled remotely by a hacker.

Once part of a zombie network, the PC can be used to launch denial-of-service attacks or send spam messages.

The SMS attacks originated in Spain and the messages are sent free of charge through network operators' SMS gateways. The messages specifically target owners of Nokia's Symbian OS based Series 60 phones, according to McAfee. 

"Enterprises would be wise to keep a close eye on this issue and think about policies for securing their mobile devices ahead of time," said Rayhawk.

"They should begin to educate their employees about the potential risk now, rather than playing catch up when it hits them."