How to enhance the safety management on Linux?

[Khemchand]

There is no absolutely secure system, even if generally agreed that a stable Linux system management and security, there are also shortcomings. We expect the system to try to take the case of low-risk work, which is necessary to strengthen the system security management. In order to help businesses understand and master the ways to enhance the Linux system in safety management, in addition to preventive work well in advance, but also need to understand the common hacking techniques. So I need to know all these.

[Calvin K]

Talking about hackers in security management, before a brief hacker attack on Linux hosts some of the main routes and modus operandi, so that everyone hackers understand the ways and means. So as to better take preventive measures, good safety precaution. To prevent the invasion of hackers intent can reduce the network within a network link with the outside world, and even independent of other networks outside the system. Hackers usually find the following ways to test a Linux or UNIX host, until it finds the goal easier to invade, and then begin hands-on invasion.

[Lillebror]

A direct tap to obtain root password, or to obtain a certain particular User's password, and the bit User may root, and then get any one User's password, since access to the general user's password is usually easy. Hackers often use some common words to crack the code. There was a hacker, said the United States, as long as with the "password" word, you can open the majority of the nation's computer. Other commonly used words are: account, ald, alpha, beta, computer, dead, demo, dollar, games, bod, hello, help, intro, kill, love, no, ok, okay, please, sex, secret, superuser , system, test, work, yes and so on.

[MrChris-]

You can use the command you can know that the computer user name above. Then look for these users to start with, and through these easy-intrusion users to obtain the system password file / etc / passwd, then password dictionary file with a password-guessing tool to guess root password. The use of general users in / tmp directory is put on the SetUID files or execute a SetUID procedures so that the root to execute to produce security vulnerabilities.

[Solomon]

Using the system in need of SetUID root privileges program vulnerabilities to obtain root permissions, such as: pppd. From Rhost host intrusion. Because when the user performs rlogin login, rlogin program will be locked. Rhost-defined host and account number, and does not require password. Modify the user. Login, cshrc,. Profile settings file such as Shell, adding some undermine the process. The user will run as long as the login.

[Devasis]

As long as the user logs on the system, they will unwittingly implement Backdoor program (which may be Crack program), it would undermine the system or to provide further system information to facilitate the penetration of the system Hacker. Hacker-line through the middle of the host, and then look for targets, with the reverse search method to avoid being caught in their real IP addresses.