System files have changed owner and group

Any idea why and how these files have changed owner and group? I beleive they should be root:root.

Code:

root@ispc6:~/bin# ls -lh  /var/spool/postfix/lib/x86_64-linux-gnu/
yhteensä 400K
-rw-r--r-- 1 web304 client99 91K touko 16  2017 libgcc_s.so.1
-rw-r--r-- 1 web304 client99 31K kesä  15 22:17 libnss_compat-2.24.so
lrwxrwxrwx 1 root   root      21 kesä  15 22:17 libnss_compat.so.2 -> libnss_compat-2.24.so
-rw-r--r-- 1 web304 client99 23K kesä  15 22:17 libnss_dns-2.24.so
lrwxrwxrwx 1 root   root      18 kesä  15 22:17 libnss_dns.so.2 -> libnss_dns-2.24.so
-rw-r--r-- 1 web304 client99 47K kesä  15 22:17 libnss_files-2.24.so
lrwxrwxrwx 1 root   root      20 kesä  15 22:17 libnss_files.so.2 -> libnss_files-2.24.so
-rw-r--r-- 1 web304 client99 19K kesä  15 22:17 libnss_hesiod-2.24.so
lrwxrwxrwx 1 root   root      21 kesä  15 22:17 libnss_hesiod.so.2 -> libnss_hesiod-2.24.so
-rw-r--r-- 1 web304 client99 47K kesä  15 22:17 libnss_nis-2.24.so
-rw-r--r-- 1 web304 client99 51K kesä  15 22:17 libnss_nisplus-2.24.so
lrwxrwxrwx 1 root   root      22 kesä  15 22:17 libnss_nisplus.so.2 -> libnss_nisplus-2.24.so
lrwxrwxrwx 1 root   root      18 kesä  15 22:17 libnss_nis.so.2 -> libnss_nis-2.24.so
-rw-r--r-- 1 web304 client99 83K kesä  15 22:17 libresolv-2.24.so
lrwxrwxrwx 1 root   root      17 kesä  15 22:17 libresolv.so.2 -> libresolv-2.24.so
root@ispc6:~/bin# 

 

It did happen again.
Now I notice that website has those files in

Code:

ls -lh web304/lib/x86_64-linux-gnu/

. I assume it is JailKit that makes that directory and the stuff therein? In that directory the files are owned by web304:client99. Of course the changed owner should not propagate to the actual OS files. I don't understand how this could happen.