REUTERS/Jim Urquhart
An analyst looks at code in the malware lab of a cyber security defense lab at the Idaho National Laboratory in Idaho Falls, Idaho September 29, 2011.
Cyber criminals have $4 by infecting computers with malicious software called "ransomware" - named for its sole function of encrypting data and holding it hostage in exchange for cash.
The FBI mentioned it as one of the "hot topics" in its $4, with nearly 2,500 complaints of ransomware reported in 2015, amounting to $1.6 million in losses.
"Ransomware and crypto malware are rising at an alarming rate and show no signs of stopping," Raj Samani, European technology head for Intel Security, $4 the BBC.
Here's what you can do to protect yourself from it.