The number of mobile ransomware victims across the globe has increased fourfold compared to a year ago, suggests a Kaspersky Lab report released last week.

Kaspersky software protected 136,532 users targeted by ransomware from April 2015 to March 2016 — up from 35,413 in the year-ago period, the company said.

“The growth curve may be less than that seen for PC ransomware, but it is still significant enough to confirm a worrying trend,” the report notes.

It identifies several factors contributing to the growth of ransomware in general:

• First, people are willing to pay the ransoms.
• Second, the value of the information stored on digital devices is so high now that paying a ransom to recover it is more cost-effective than not paying the ransom.
• Third, law enforcement is having difficulty responding to the problem.
• Fourth, new payment tools make it easier for extortionists to collect ransoms.