Linux Files cannot be modified or edited by the root user.

Linux Files cannot be modified and edited by the root user. Recently, a company's server was maliciously added some timer tasks to the crond configuration file "/var/spool/cron/root "., in this case, you only need to simply use the crontab-e command to remove the malicious task. However, after the modification, I found that no matter how hard I try to save it, directly modifying the file "/var/spool/cron/root" won't work either. I have a hard time thinking about the power to make it impossible for the root user with the highest power to modify and delete the file. Www.2cto.com later, after a friend of senior Linux clicked it, he knew that the file had lower-level file attributes besides read/write permission control, here, the two commands used to view and change the file properties are lsattr and chattr. Use lsattr/var/spool/cron/root to check whether the file has been added with the sia attribute: s --- ia -------/var/spool/cron/root. Then use: chattr-isa/var/spool/cron/root removes these three attributes to modify the file and successfully remove the malicious task. Www.2cto.com