A method of evaluating cyber-security threat incidents of a computer network using a device , the method comprising: presenting graphical objects (11-19) on a user interface of a display of the device , whereby each graphical object (I1- I9) represents a cyber-security threat incident; receiving a single continuous touch input through a touch interface of the user interface , the continuous touch input selecting a subset of the graphical objects ; generating a risk score for the subset of the graphical objects , whereby the risk score is generated by: retrieving a list of computer assets associated with the computer network and severity weightage values accorded to each of the computer assets , whereby for each graphical object (11-19), identifying computer assets that are affected by the threat incident represented by the graphical object (11-19) and summing the severity weightage values of the identified computer assets , and dividing the summed severity weightage values by the sum of severity weightage values of all the computer assets to obtain an incident score for each graphical object (11-19), and calculating the risk score by dividing a sum of the incident scores of all the graphical objects (I1, 12, 15, 16, 17) in the subset of graphical objects by a total number of graphical objects in the subset of graphical objects and by multiplying the result with a 100; displaying the generated risk score on the display of the device ; and executing mitigation actions for graphical objects in the subset of graphical objects if the generated risk score exceeds a confidence score. presenting graphical objects (11-19) on a user interface of a display of the device , whereby each graphical object (I1- I9) represents a cyber-security threat incident; receiving a single continuous touch input through a touch interface of the user interface , the continuous touch input selecting a subset of the graphical objects ; generating a risk score for the subset of the graphical objects , whereby the risk score is generated by: retrieving a list of computer assets associated with the computer network and severity weightage values accorded to each of the computer assets , whereby for each graphical object (11-19), identifying computer assets that are affected by the threat incident represented by the graphical object (11-19) and summing the severity weightage values of the identified computer assets , and dividing the summed severity weightage values by the sum of severity weightage values of all the computer assets to obtain an incident score for each graphical object (11-19), and calculating the risk score by dividing a sum of the incident scores of all the graphical objects (I1, 12, 15, 16, 17) in the subset of graphical objects by a total number of graphical objects in the subset of graphical objects and by multiplying the result with a 100; retrieving a list of computer assets associated with the computer network and severity weightage values accorded to each of the computer assets , whereby for each graphical object (11-19), identifying computer assets that are affected by the threat incident represented by the graphical object (11-19) and summing the severity weightage values of the identified computer assets , and dividing the summed severity weightage values by the sum of severity weightage values of all the computer assets to obtain an incident score for each graphical object (11-19), and calculating the risk score by dividing a sum of the incident scores of all the graphical objects (I1, 12, 15, 16, 17) in the subset of graphical objects by a total number of graphical objects in the subset of graphical objects and by multiplying the result with a 100; displaying the generated risk score on the display of the device ; and executing mitigation actions for graphical objects in the subset of graphical objects if the generated risk score exceeds a confidence score. <EOS>