A computer implemented method of disabling a malicious electronic control unit, ECU, of a plurality of ECUs in communication with a controller area network, CAN, bus network, the method executed by a computing device in communication with the plurality of ECUs (204, 208) and the CAN bus network, the method comprising: detecting a malicious message transmitted by the malicious ECU over the CAN bus network; injecting a plurality of bits over the CAN bus network to trigger a predefined plurality of errors for disabling the malicious ECU before the malicious ECU makes an additional attempt to retransmit an additional instance of the malicious message; wherein the predefined number of the plurality of errors are triggered by a plurality of injection sessions, wherein each bit injection session is triggered in response to detection of an additional error; characterized in that: wherein a first injection session of the plurality of injection sessions comprises injecting bits to trigger a first error and transmission of a first error flag, wherein a current error count value stored by at least one error counter of the malicious ECU is increased by the transmission of the first error flag; and further comprising: interrupting the error frame storing the first error flag and injecting bits as an additional bit injection session for manipulating the form of the error frame to trigger a form error, wherein the form error triggers transmission of another error flag which triggers another increase of the current error count value stored by the at least one error counter of the malicious ECU; iterating the interrupting of an additional error frame and the injection of bits as an additional bit injection session for manipulating the form of the error frame, to trigger at each iteration the transmission of a form error form and a respective increase of the current error count value, wherein the number of iterations are performed accordingly to generate the predefined number of the plurality of errors for disabling the malicious ECU. detecting a malicious message transmitted by the malicious ECU over the CAN bus network; injecting a plurality of bits over the CAN bus network to trigger a predefined plurality of errors for disabling the malicious ECU before the malicious ECU makes an additional attempt to retransmit an additional instance of the malicious message; wherein the predefined number of the plurality of errors are triggered by a plurality of injection sessions, wherein each bit injection session is triggered in response to detection of an additional error; characterized in that: wherein a first injection session of the plurality of injection sessions comprises injecting bits to trigger a first error and transmission of a first error flag, wherein a current error count value stored by at least one error counter of the malicious ECU is increased by the transmission of the first error flag; and further comprising: interrupting the error frame storing the first error flag and injecting bits as an additional bit injection session for manipulating the form of the error frame to trigger a form error, wherein the form error triggers transmission of another error flag which triggers another increase of the current error count value stored by the at least one error counter of the malicious ECU; iterating the interrupting of an additional error frame and the injection of bits as an additional bit injection session for manipulating the form of the error frame, to trigger at each iteration the transmission of a form error form and a respective increase of the current error count value, wherein the number of iterations are performed accordingly to generate the predefined number of the plurality of errors for disabling the malicious ECU. wherein a first injection session of the plurality of injection sessions comprises injecting bits to trigger a first error and transmission of a first error flag, wherein a current error count value stored by at least one error counter of the malicious ECU is increased by the transmission of the first error flag; and further comprising: interrupting the error frame storing the first error flag and injecting bits as an additional bit injection session for manipulating the form of the error frame to trigger a form error, wherein the form error triggers transmission of another error flag which triggers another increase of the current error count value stored by the at least one error counter of the malicious ECU; iterating the interrupting of an additional error frame and the injection of bits as an additional bit injection session for manipulating the form of the error frame, to trigger at each iteration the transmission of a form error form and a respective increase of the current error count value, interrupting the error frame storing the first error flag and injecting bits as an additional bit injection session for manipulating the form of the error frame to trigger a form error, wherein the form error triggers transmission of another error flag which triggers another increase of the current error count value stored by the at least one error counter of the malicious ECU; iterating the interrupting of an additional error frame and the injection of bits as an additional bit injection session for manipulating the form of the error frame, to trigger at each iteration the transmission of a form error form and a respective increase of the current error count value, wherein the number of iterations are performed accordingly to generate the predefined number of the plurality of errors for disabling the malicious ECU.