A ransomware is a malicious software that takes personal data hostage. He encrypts personal data and asks the owner for money in exchange for the decryption key.
A ransomware typically spreads in the same way as a Trojan Horse: it penetrates the system for example via Web Exploit or through email-malicious campaigns. In any case, a ransomware will try to extort money from the user, by having him buy a program to decrypt his files.
The means of fight recommended against a crypto-locker are the following:
- Disconnect infected devices from shared networks, wired or wireless.
- Change your passwords after cleaning the network.
- Make regular backups of his data, and store them offline.
- Consult a computer security expert for instructions.
* This information was collected on https://en.wikipedia.org/wiki/Ransomware