How did hackers compromise Mark Zuckerberg's Facebook page?

a$.$

Created a fake Facebook account impersonating Zuckerberg

b$.$

Exploited a vulnerability in the Facebook API to post unauthorized status updates

c$.$

Sent phishing emails to Mark Zuckerberg

d$.$

Manipulated the security screening system on Facebook

e$.$

Used malware to gain access to Zuckerberg's login credentials