My bank is asking me to re reigister my mortgage loan,why do I have to re register?

Let me guess - an email you received.

Change your email password immediately.

When you went into a strange site, and they asked you for your email and password, you may have actually typed it.

If this is the case, someone else is reading your emails.

They can see what banks you use and send you scam mail.

Yes, they are some people that will (by mistake) put their email and password in a strage site when asked. Easy to do if you are not paranoid in the internet.

Use different ID's and passwords for every single site you hit.

And keep a notebook of it called recipes or bible verses.

A likely scam. Call your bank at the number printed on your monthly statement.