The journalists are believed to have listened to voicemail messages but, said Mr Stanley, changes introduced by UK network operators in recent months made it harder for anyone but the correct customer to listen to those messages.

BBC: How easy is it to hack a mobile?

Similar to spam messages that have corrected their grammar and use correct imagery and CSS, the attackers selling fake anti-virus are getting more professional.

FORBES: Fake Anti-Virus Software Targets Firefox Users