Some practical skills for preventing hackers in Linux

Article Title: some practical skills for preventing hackers in Linux. Linux is a technology channel of the IT lab in China. Including desktop applications, Linux system management, kernel research, embedded systems, open-source and other basic classification Linux is a multi-user system, once people get your root user, he can do whatever he wants on your system. Because a single user has full control permissions on the system, the consequences of improper operations or access by others will be unimaginable, pay attention to the following aspects to prevent single-user access.

1. Protect the/etc/inittab file. If you change 3 in id: 3: initdefault to 1, you can directly access the single-user mode at each startup. For the/etc/inittab file, use the root identity to enter the chown 700/etc/inittab and set the attribute to something other users cannot modify.

2. If the lilo mode is used for boot, you may use linuxconf or directly modify lilo. conf to set the waiting time for the boot to 0 or the shortest time. In this case, if you enter the single-user mode, you can use a floppy disk for boot.

3. If GRUB is used for boot, the simplest method is to use the GRUB Password to protect the startup options.

4. In order to prevent remote damage and restart the system, in addition to effectively managing the ROOT password and files in the/etc directory, the CMOS password should also be set, in this way, even if the system is changed to a single user mode, the computer cannot be started directly.