The number of ATMs in the US compromised by criminals rose 546 percent in 2015 over 2014, according to analytic software firm FICO.

Criminal activity was highest at non-bank ATMs, such as those in convenience stores, where 10 times as many machines were compromised as in 2014. FICO first reported on the sharp growth in ATM fraud on its blog last May.

FICO also reported that ATM compromises were taking place over fewer days. The average duration of an ATM compromise fell from 36 days in 2014 to 14 days in 2015. The average number of cards affected by a compromise was cut in half.

“Criminals are taking a quick-hit approach to ATM theft and card fraud,” said TJ Horan, vice president of fraud solutions at FICO. “They are moving faster to make it harder for banks to react and shut down the compromises. They are targeting non-bank ATMs, which are more vulnerable — in 2015, non-bank ATMs accounted for 60 percent of all compromises, up from 39 percent in 2014.”

ATM compromises in 2015 also spread out across the country, whereas in 2014 the compromises were concentrated in large cities on the East Coast and West Coast. Horan said that ATM operators need to increase the frequency of their inspections, looking carefully for any signs of tampering.

Read more: http://www.fico.com.