Security of Linux’s Network – User and Group
Wisdom words : Victory belongs to the last second man who was wrong.
The hacker’s target why they attack your system is get the privilege of root. If they’ve gotten this privilege,they could do anything they want. So the security problem of Linux is concentred in administration of accout,file system and application services.
Many Linux users think their system which have no important information would not be attacked by hackers. They are wrong. Hackers always used these machines have been conquered to attacked other more important computers which are their really targets.
All the account’s information are stored in the file named “/etc/passwd” whose each line indicates the information of indentified accout. The root account’s user id is “0”(number zero). Those users whose id is “0” have the root privilege whatever their names are. For example. both toor and super belong to root. System account which belong to nobody would never login because they are used for special application.For example, “nobody” account response the user’s http request, and the “lp” account works on print request.
Summary: Three type account of Linux: root(toor,super), system account(nobody,lp), general account.