Facebook got hacked and scammed around $20,000 Consumer Fraud

Good day,

Let me start by saying that my father's(64yrs old) facebook account got hacked, it happend when a certain person asked a favor for my father by liking her daughter's photo, unfortunately that site was a phising site and managed to obtain all the information by my father.

After which that hacker messaged a lot of people from my father's account and managed to scam around $20,000. The way the hacker did was to send money through 7/11 store and send it to coins.ph(e-wallet).

We noticed way too late as some of my father's friend already sent money to coins.ph

I need to ask question or advice if we are obliged to pay the money that were scammed? And also what legal action should we take.

Thank you.