Determining a reproduction number for a malware

A computer implemented malware protection method to protect at least a subset of a set of computer systems from a malware, the method comprising:

• accessing a model of the set of computer systems;
• simulating a propagation of the malware through the set of computer systems using the model, wherein the simulating comprises a method including:
• identifying a plurality of first simulated computer systems infected with a simulated malware;
• for each of the first simulated computer systems, infecting a number of neighbouring second simulated computer systems, the number being zero or an integer;
• and
• determining a value of a reproduction number, R0, based on the total number of second simulated computer systems and the number of first simulated computer systems;
• and
• identifying, based on the determined value(s) of the reproduction number, R0, one or more malware protection measures to be deployed to one or more of the set of computer systems.

A system including one or more processors and a memory storing instructions that, when executed by the one or more processors, cause the one or more processors to simulate a propagation of a malware through a set of computer systems by at least being configured to:

• identify a plurality of first simulated computer systems infected with a simulated malware;
• for each of the first simulated computer systems, infect a number of neighbouring second simulated computer systems, the number being zero or an integer;
• and
• determine a value of a reproduction number, R0, based on the total number of second simulated computer systems and the number of first simulated computer systems.