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Hackers like WordPress sites and your blogs too. With some precautious steps you could avoid your WordPress driven website being hacked.
WordPress codex has a detailed article on Hardening wordpress, and hence hardening your site. In fact its a guide to help you to find and prevent your PC vulnerabilities, Server Vulnerabilities, WordPress package issues, Your network issues, Database, Files etc.
Go on here to read further to learn to secure your site.