You work as a professional Ethical Hacker. You are assigned a project to perform blackhat mechanic. You claim that someone from the office called you saying that there is some fault in the air-conditi

You work as a professional Ethical Hacker. You are assigned a project to perform blackhat mechanic. You claim that someone from the office called you saying that there is some fault in the air-conditioner of the server room. After some inquiries/arguments, the Security Administrator allows you to repair the air-conditioner of the server room. When you get into the room, you found the server is Linux-based. You press the reboot button of the server after inserting knoppix Live CD in the CD drive of the server. Now, the server promptly boots backup into Knoppix. You mount the root partition of the server after replacing the root password in the /etc/shadow file with a known password hash and salt. Further, you copy the netcat tool on the server and install its startup files to create a reverse tunnel and move a shell to a remote server whenever the server is restarted. You simply restart the server, pull out the Knoppix Live CD from the server, and inform that the air-conditioner is working properly. After completing this attack process, you create a security auditing report in which you mention various threats such as social engineering threat, boot from Live CD, etc. and suggest the countermeasures to stop booting from the external media and retrieving sensitive data. Which of the following steps have you suggested to stop booting from the external media and retrieving sensitive data with regard to the above scenario? Each correct answer represents a complete solution. Choose two.