/etc/issue
contains a message or system identification to be printed before the login prompt.
/etc/profile
controls system-wide default variables, such as Export variables, File creation mask (umask), Terminal types, Mail messages to indicate when new mail has arrived
/proc/version
specifies the version of the Linux kernel
/proc/cpuinfo
Shows CPU info
/proc/meminfo
Shows meme info
/etc/passwd
has all registered user that has access to a system
/etc/group
contains groups on the machine
/etc/shadow
contains information about the system’s users’ passwords
/root/.bash_history
contains the history commands for root user
/var/log/dmessage
contains global system messages, including the messages that are logged during system startup
/var/mail/root
all emails for root user
/root/.ssh/id_rsa
Private SSH keys for a root or any known valid user on the server
/var/log/apache2/access.log
the accessed requests for Apache webserver
C:\boot.ini
contains the boot options for computers with BIOS firmware