A drone unit operatively connected to a server may identify an attack, launched by a botnet, on a resource. A drone unit may continuously and iteratively, while the attack is in progress, determine and report to a server a first set of values of a respective set of operational parameters related to the resource. A drone unit may determine, and report to the server, a second set of values of the set of operational parameters after the attack is terminated. A server may determine an impact of an attack by relating the first set values to the second set of values.