“Ransomware” threat is on the rise, but the bad news is that Ransomware campaigns are easier to run. One dark web hacker has released a ransomware-as-a-service kit, dubbed “Tox,” for anyone to download and set up their own ransomware for free. The developers of the online software make money by taking a cut (20%) of any successful ransomware campaigns its users run. The Tox site (runs on the TOR network) will track the installs and profit.
Source: https://thehackernews.com/2015/05/ransomware-creator.html

