我被駭了!!SOS

[ge99]

各位大大：
在下ls指令時發現權限被改掉了，我要怎麼改回來呢？用root進去改居然
chown root:root ls
chown: ls: Operation not permitted
怎麼辦呢????


-rwxr-xr-x 1 root root 19836 Aug 25 2000 ln
-rwxr-xr-x 1 root root 73916 Aug 28 2000 loadkeys
-rwxr-xr-x 1 root root 19464 Aug 31 2000 login
-rwx------ 1 root lp 43740 May 30 13:06 ls
-rwxr-xr-x 1 root mail 67740 Aug 24 2000 mail
-rwxr-xr-x 1 root root 17660 Aug 25 2000 mkdir
-rwxr-xr-x 1 root root 15964 Aug 25 2000 mknod
-rwxr-xr-x 1 root root 4376 Jul 12 2000 mktemp
-rwxr-xr-x 1 root root 23900 Aug 31 2000 more
-rwsr-xr-x 1 root root 55356 Aug 5 2000 mount
-rwxr-xr-x 1 root root 42076 Aug 25 2000 mv
-rwx------ 1 root lp 78012 May 30 13:05 netstat
-rwxr-xr-x 1 root root 6848 Jul 13 2000 nice

[pcboy]

chown +x +r +w ls
chown root:root ls