| Attack | Prevention |
| Reformatting a disk partition, writing garbage data to a raw partition, or running the newfs /mkfs command | Prevent anyone from accessing the machine in single- user mode. Protect the superuser account. Physically write-protect disks that are used read-only. |
| Deleting critical files (e.g., needed files that are in /dev or the /etc/passwd file) | Protect system files and accounts by specifying appropriate modes (e.g., 755 or 711). Protect the superuser account. Set ownership of NFS-mounted files to user root and export read-only. |
| Shutting off power to the computer | Put the computer in a physically secure location. Use uninterruptible power supplies . Put a lock on circuit-breaker boxes, or place them in locked rooms. (However, be sure to check the National Electric Code Section 100 regarding the accessibility of emergency shutoffs. Remember that a computer that is experiencing an electrical fire is not very secure.) |
| Cutting network or terminal cables | Run cables and wires through conduits to their destinations. Restrict access to rooms where the wires are exposed. |
| Car or truck bombs blowing up the building containing the computer | Provide for redundant off-site computer systems and storage. |