Win2003 stopped supporting in July this year. Microsoft issued a document encouraging users to migrate as soon as possible

Today's official Microsoft blog author encourages users to migrate away from Windows Server 2003 as soon as possible. This system, which has been in use for 12 years, will stop supporting in July this year. Microsoft encourages companies to migrate to Windows Server 2012 R2, Microsoft Azure or On Office 365.

In this article by Takeshi Numoto, vice president of cloud computing and corporate marketing at Microsoft, explaining the risk of continuing to use Windows Server 2003 after the service has stopped:

Of course Windows Server 2003 will still be able to run after it stops supporting. But running an unsupported operating system will create significant security risks and ultimately lead to expensive post-costs. When you evaluate security risks, Microsoft is here to remind you that an unpatched server is very likely to be the target of hacking.