Mobile malware took off in 2011. That is when hackers began serious attacks on mobile phones, says David Emm, principal security researcher, at Kaspersky Lab, a cyber security company.
“At that point, the data became worth stealing, and since then growth has been exponential,” Mr Emm says. He estimates 1m new malicious codes were found on devices in 2015. “The actual number of attacks is much bigger than this because each program tends to be used many times.”
Early attacks focused on causing handsets silently to call premium rate numbers. Then hackers diversified into phishing — creating spoof websites that trick people into revealing account numbers and login details.