The US Computer Emergency Response Team (CERT) has warned IT managers to migrate their systems from Microsoft's Windows Server 2003 operating system before the 14 July 2015 cut off or face dire consequences.
Failure to do so could leave firms exposed to greater security threats, and at risk of breaching compliance regulations.
"As of July 2014, there were 12 million physical servers worldwide still running Windows Server 2003," said CERT in an advisory.
"Computer systems running unsupported software are exposed to an elevated risk of cyber security dangers, such as malicious attacks or electronic data loss.
"Organisations that are governed by regulatory obligations may find they are no longer able to satisfy compliance requirements while running Windows Server 2003."
The advisory said that companies should consider using a third-party software solution to speed up the migration process.
"Users have the option to upgrade to a currently supported operating system or other cloud-based service," said CERT.
"There are software vendors and service providers in the marketplace who offer assistance in migrating from Windows Server 2003 to a currently supported operating system or software as a service/infrastructure as a service products."
V3 recently heard from Dell who said that many organisations it is working with to migrate away from Windows Server 2003 are finding the biggest challenges are around complexity, rather than technical issues.
Windows Server 2003's cut off follows the end of support for Microsoft's Windows XP operating system in April. Despite the end of official support numerous firms have continued to use XP.
Use of Windows XP dropped below 20 percent for the first time in November, according to figures from Netmarketshare.com.
The slow migration has been a constant headache in the security community as several attacks have been uncovered targeting known, but unpatched, vulnerabilities in Windows XP.
Russian security firm Kaspersky uncovered an espionage network targeting government institutions, spy agencies and European industries using a Windows XP flaw in August.
Prior to this, researchers from FireEye uncovered an 'Operation Clandestine Fox' campaign in May exploiting a zero-day vulnerability in Microsoft's Internet Explorer to target Windows XP users.
Microsoft seizes control of phishing sites linked with Russian state hackers
Fitness trackers over-estimate the number of steps their users take, analysis of 67 research reports suggests
Everything we think we know about the imminent Apple iPhone 9, iPhone 11 and iPhone 11 Plus launches
All the latest rumours about Apple iPhone Displays, CPUs, launch dates and even prices
Nvidia brings Turing microarchitecture into the high-end gaming segment