CNBC take a look at the biggest threats to your online world in 2015. Beware: ransomware Ransomware -- a type of malware which restricts access to the computer system that it infects –will become increasingly sophisticated in its methods and targets, experts at McAfee Labs warned. "We predict ransomware variants that manage to evade security software installed on a system will specifically target endpoints that subscribe to cloud-based storage solutions such as Dropbox, Google Drive, and OneDrive. Once the endpoint has been infected, the ransomware will attempt to exploit the logged-on user's stored credentials to also infect backed-up cloud storage data," McAfee's report on 2015 cyber risks noted. Ransomware encrypts data and McAfee thought attacks on mobile devices and cloud-backed data would increase.