Is the "Termination of your yahoo webmail account" email legitimate? Or just spam?

The message is as following:

Dear Staff/Subcribers

TERMINATION OF YOUR YAHOO WEBMAIL ACCOUNT

We are currently carrying out an upgrade on our system due to the fact that

it has come to our notice that one or more of our subscribers are

introducing a very strong virus into our system and it is affecting our

network.We are trying to find out the specific person.

For this reason all subscribers are to provide their USER NAME AND PASSWORD

for us to verify and have them cleared against this virus.

Failure to comply will lead to the termination of your Account in the next

48 hours.

Information to send;

EMAIL ADDRESS:

USERNAME:

PASSWORD:

Hoping to serve you better.

Sincerely,

YAHOO mail Support

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This is an Administrative Message from YAHOO Mail server. It is not

spam. From time to time, YAHOO mail server will send you such messages

in order to communicate important information about your subscription.

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