A method of evaluating cyber-security threat incidents of a computer network using a device (100, 215), the method comprising: presenting graphical objects on a user interface (102, 305) of a display (140, 305) 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 (145, 205, 310) of the user interface (140, 305), 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, identifying computer assets that are affected by the threat incident represented by the graphical object 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, 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 on a user interface (102, 305) of a display (140, 305) 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 (145, 205, 310) of the user interface (140, 305), 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, identifying computer assets that are affected by the threat incident represented by the graphical object 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, 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, identifying computer assets that are affected by the threat incident represented by the graphical object 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, 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.