Security

I have been given a task of submitting a list of websites to be blocked at my organization. I am a part of Cyber team. The intent here is to block some known malicious websites which can cause harm intentionally or unknowingly. Also to prevent insider threat such as data leak.

Can anyone please suggest me couple of websites to get started with. I have already blocked kickass torrents and thepiratebay.

Note: The aim here is not to block websites to reduce waste of time such as Facebook, Redditt, etc.