Information
The /etc/group- file contains a backup list of all the valid groups defined in the system.
Rationale:
It is critical to ensure that the /etc/group- file is protected from unauthorized access. Although it is protected by default, the file permissions could be changed either inadvertently or through malicious actions.
Solution
Run the following commands to set owner, group, and permissions on /etc/group-:
# chown root:root /etc/group-
# chmod u-x,go-wx /etc/group-