The two entry routes for this type of malware are: the exploitation of vulnerabilities within the system itself and the human factor (according to Zaharia in 2017, 97% of phishing mails contained some form of ransomware).
This type of malware is neither new nor current. In 1980, there was already some ransomware, such as PC Cyborg. Later came CryptoLocker. These were followed by many others, such as TeslaCrypt, WannaCry, Ryuk...
What is Ryuk and what happened to the SEPE?
On 9 March, the SEPE announced on Twitter that its website and its electronic headquarters were unavailable... It was a cyber-attack.
The SEPE was infected by Ryuk (a name that refers to the manga Death Note), a type of ransomware that likes large Microsoft Windows systems of public entities (it is unknown how it penetrated, but it arrived just when a Microsoft Exchange Server vulnerability called ProxyLogon was detected... Draw your own conclusions).
Ryuk also left other "gifts" around Spain in companies such as Prosegur, Everis or Cadena Ser, as well as in some city councils.