Help with Security - Compromised Accounts

[foreright]

I have recently received emails from eBay, Microsoft & Amazon informing me of actual or attempted change of passwords.
I know that my eBay account was hacked and a trader in Casablanca, Morocco put items up for same using my account. Amazon was an attempt and my password was changed on my Microsoft account.
I have closed my Amazon account and thought things were sorted at eBay before another attempt this morning, which has prompted me to close that too (although it is a long winded procedure)
Can anyone offer advice /info how hacking is achieved as I haven't used my eBay or amazon account for months and what point is there of hacking a Microsoft account.
Please help and offer any advise of which device to purge and future prevention.

 

[foreright]

Thanks for the replies, I shall investigate 2fa and set that up (assuming I can)
What I cannot understand is how the passwords for the 2 of the accounts were changed when there is no info on my email account for it except to say that "was it me". The Amazon account sent a code to reset the password but I assume hacker couldn't infiltrate my email account to access it but successfully changed the password on my eBay and Microsoft accounts another way.

Am I right in thing my secure key with HSBC is a form of 2fa. If that is correct, what ways would have been my option on Amazon and eBay say?

 

[foreright]

Thanks all, for the help and advice.