Question

a class of malware which restricts access to the computer system that it infects, and demands a ransom paid to the creator of the malware in order for the restriction to be removed

Accepted Answer

ransomware

Przód	a class of malware which restricts access to the computer system that it infects, and demands a ransom paid to the creator of the malware in order for the restriction to be removed
Tył	ransomware

Malware Class Restricts Access Computer System Infects Demands