You have find many discussion about WordPress is not secure or easy to hack. I will share some of plugin which can make your website more secure.

Google Authenticator

The Google Authenticator plugin for WordPress gives you two-factor authentication using the Google Authenticator app for Android/iPhone/Blackberry.

Download here

Limit Login Attempts

Limit the number of login attempts possible both through normal login as well as using auth cookies.

Download here

BackWPup Free – WordPress Backup Plugin

Schedule complete automatic backups of your WordPress installation. Decide which content will be stored (Dropbox, S3…). This is the free version

Download here

Disclaimer: You have to check plugin details before your installing that its has to be compatible with your website version