Answer Description
This type of malware is called Ransomware. It holds data or information ransom until a fee is paid after which point it will return the information or data (or so it says...). Based on the information available in the question this is the only conclusion we can make. It is possible as the CEO of the company they were targeted specifically via social media (spear phishing) but there isn't definitive evidence of this yet.
Wikipedia
Ransomware is a type of malware from cryptovirology that threatens to publish the victim's data or perpetually block access to it unless a ransom is paid. While some simple ransomware may lock the system in a way which is not difficult for a knowledgeable person to reverse, more advanced malware uses a technique called cryptoviral extortion, in which it encrypts the victim's files, making them inaccessible, and demands a ransom payment to decrypt them. In …
Ransomware - Wikipedia, the free encyclopedia