You need to download Microsoft's patch for 19-year-old bug right now

It has taken Microsoft 19-years to release a patch for a critical security bug in its software.

The security bug, named WinShock, was discovered by a team from US technology firm IBM earlier this year in May, and they found the problem has been present in every version of Windows dating back to Windows 95.

IBM and Microsoft only announced the news today after taking the decision to keep it silent for the past six months until a fix was put into place.

In a blogpost, IBM researcher Robert Freeman claimed the bug would allow cybercriminals to carry out 'drive-by attacks', which means making vulnerable users install malicious software.

Attackers could then run code over the infected computer and actually take remote control of it.

IBM claim that the bug had been sitting in plain sight, which makes you wonder why it took 19-years for the bug to be identified and fixed.

The severity of WinShock can be truly released by the fact it was given a huge 9.3 out 10 on the Common Vulnerability Scoring System (CVSS), an industry standard system that scores the severeness of software vulnerabilities.

Some in the computing industry have compared its significance to the other major software flaw discovered this year HeartBleed, which caused quite media frenzy.

According to reports, WinShock is much more difficult to utilise and at present there is no known evidence that points to the bug being exploited by cybercriminals or hackers.

Microsoft pushed out 14 patches yesterday in an effort to address the 19-year-old problem, with two more updates said to be in the pipeline. IBM and Microsoft urges user to make sure the patch is installed through Windows Update as soon as possible.