Security

See also: Firewalls, Permissions

Anti-Virus

clamscan

A free and open source anti-virus command line utility. Run “freshclam” to update the anti-virus database.

Usage

Explanation

-r

recursively through folders

-i

only output infected files

–move=<PATH>

specify path to move infected files to

Audit

Package: audit

For Audit to work properly, the service needs to be started.

$ sudo systemctl start auditctl

auditctl

Log verbose modifications and access to a file.

Usage

Explanation

-w

watch a file

-p arwx

watch for appending, reading, writing and executing of the file

ausearch

used after setting up auditctl on a file

Usage

Explanation

-f

views log of a given file

-t

check for changes during a certain time

Kerberos

kadmin (Command)

Package: krb5-workstation

Manage the Kerberos Distribution Center (KDC).

Usage

Explanation

-q

run interactive commands

kadmin (Interactive)

Usage

Explanation

?

view the available commands

addprinc <USER>

create a new principal for a user

addprinc host/<HOSTNAME>

create a new principal to allow authentication from a server

addprinc nfs/<HOSTNAME>

create an NFS principal

addprinc cifs/<HOSTNAME>

create a CIFS/SMB principal

addprinc ftp/<HOSTNAME>

create a FTP principal

ktadd host/<HOSTNAME>

save the principal to the /etc/krb5.keytab file

ktremove host/<HOSTNAME>

remove the principal from the keytab file

delprinc

delete a principal

listprincs

list principals

klist

View authentication information about Kerberos.

Usage

Explanation

show the current ticket validation status

-k

show the contents of the /etc/krb5.keytab file

kdestroy

Revoke a user’s Kerberos ticket.

Usage

Explanation

write zeros to the cached ticket file to securely remove it

Local System

Miscellaneous commands for managing security on local systems.

genkey

Package: crypto-keys

Generate SSL/TLS certificates.

Usage

Explanation

<DOMAIN_NAME>

create a self-signed SSL

gpg

Package: gnupg

Usage

Explanation

–output <NEW_FILE>.gpg –encrypt <FILE>

encrypt a specified file, saving it as a new file

–output <FILE> –decrypt <NEW_FILE>.gpg

decrypt an encrypted file, saving it as a new file

lastb

Package: util-linux

Usage

Explanation

shows last failed login attempts

lastlog

Package: shadow-utils

Usage

Explanation

shows inform about the last logins

sudo

Package: sudo

Allow non-root accounts to temporarily run privileged commands.

Usage

Explanation

-E

keeps sudo enabled for the current shell session