please help if how i know if this scam

Hi I am Claire from Philippines I meet host family in nanny.com
Host family message me that send me photo or resume after while she send me a contract letter to sign and she told me that send to UK_border office email.com
After while they send me a application work permit and instruction what I need to send or what is the requirement with a 850 GBP proof of sufficient fund(SPF)that I need to scan send to that email receiver was me.if this legal or scam how I know if its true how I check to the UK home if somebody hired me as a au pair.going to London hope someone answer me soon

[AlanJones]

It's a definite scam - the UK visa program for au pairs is restricted to nationals of only a few countries and The Philippines is not one of them, so anyone claiming to offer you a job in the UK is a scammer.

Please post the email addresses of the fake family and the UK home office, together with the emails that they sent you as other victims may be searching for them.