Mobile phone viruses and spam looks set to rise, says the Georgia Institute of Technology Information Security Center (GTISC).
According to its annual Emerging Cyber Threats report, cybercriminals will start targeting smartphones as they are being used more frequently by users when it comes to finacial matters and therefore are a source of sensitive personal data such as credit card and bank account details.
The GTISC also said its expected spam and virus attacks to take the same form as those that are designed to attack PCs.
Simeon Coney of Adaptive Mobile, which provides security software mobile phones, told the BBC: "One of common types we see now runs amok on the Symbian platform. These viruses work their way through the contact book, sending themselves out to every subscriber who has been called or has called that handset".
Coney said there are 100,000 mobile virus attacks a day but most users are not affected as many mobile viruses are not very sophisticated. He advised mobile users to use precautions similar to those exercised when using a PC.
"Think twice before running any attachment from someone you don't know, check your bill on a regular basis, and ensure your Bluetooth connection is not set in discoverable mode."
The Emerging Cyber Threats Report suggested mobile operators, handset manufacturers and application developers need to work together in securing handsets.