A computer implemented method for recommending a defense strategy for managing network vulnerability, wherein the network comprises a plurality of devices, the method comprising the steps of: - identifying the vulnerability level v i of each i of said plurality of devices, - identifying the importance level r i of each i of said plurality of devices, - estimating the damage induced on the network when at least one of the devices is being attacked by at least one attacker while at least one of the devices is being defended by at least one defender, comprising the step of evaluating said vulnerability level v i and said importance level r i of at least one of the corresponding devices i, - defining a game theory security game using said estimated damage and solving the security game, - computing a strategy which corresponds to a solution of said security game for recommending a defense strategy for managing the network vulnerability, - wherein said step of defining the game theory security game, comprises the step of generating an Nr×Nr game-matrix |P( i,j)|, wherein selecting the first index in the first dimension of the game matrix corresponds to selecting a device being attacked by an attacker and wherein selecting the second index in the second dimension of the game-matrix corresponds to selecting a device treated by a defender to lower its attack vulnerability, - wherein said solution of the security game is obtained by solving a two player attacker-defender security game, wherein the players of the two player attacker-defender security game are abstract players, each comprising one or more players, - wherein the entries of said game-matrix |P( i,j)| are defined as Fuzzy-membership functions, - wherein the vulnerability and importance values are represented by five levels and quantified by v, r ∈{1,2,3,4,5} and wherein the vulnerability level of a device is chosen to be the maximum value of the vulnerabilities of categories it belongs to. - identifying the vulnerability level v i of each i of said plurality of devices, - identifying the importance level r i of each i of said plurality of devices, - estimating the damage induced on the network when at least one of the devices is being attacked by at least one attacker while at least one of the devices is being defended by at least one defender, comprising the step of evaluating said vulnerability level v i and said importance level r i of at least one of the corresponding devices i, - defining a game theory security game using said estimated damage and solving the security game, - computing a strategy which corresponds to a solution of said security game for recommending a defense strategy for managing the network vulnerability, - wherein said step of defining the game theory security game, comprises the step of generating an Nr×Nr game-matrix |P( i,j)|, wherein selecting the first index in the first dimension of the game matrix corresponds to selecting a device being attacked by an attacker and wherein selecting the second index in the second dimension of the game-matrix corresponds to selecting a device treated by a defender to lower its attack vulnerability, - wherein said solution of the security game is obtained by solving a two player attacker-defender security game, wherein the players of the two player attacker-defender security game are abstract players, each comprising one or more players, - wherein the entries of said game-matrix |P( i,j)| are defined as Fuzzy-membership functions, - wherein the vulnerability and importance values are represented by five levels and quantified by v, r ∈{1,2,3,4,5} and wherein the vulnerability level of a device is chosen to be the maximum value of the vulnerabilities of categories it belongs to.