Windows XP has lower infection rate than Vista and 7

Microsoft's bi-annual Security Intelligence Report (SIR) has revealed the Windows 7 and Windows Vista operating systems are more at risk of being infected by malware that Windows XP.

Windows XP computers were prone to infections at a rate of 2.42 per cent, while Windows Vista and Windows 7 had an infection rate of 3.24 per cent and 2.59 per cent, figures from the last quarter of 2013 showed.

Windows 8 and Windows 8.1 computers are least likely to be infected by malware, with a 1.3 per cent and 0.08 per cent infection rate respectively.

The reason why Windows 7 and Vista are more likely to be affected by malicious software is because of the Rotbrow' malware targeting browsers.

The Rotbrow program pretends to be a browser add-on, supposedly used to protect your computer against malware. However, it then starts downloading malicious browser extensions that can attack your computer and give access to personal details.

The vulnerability was discovered by Microsoft, which then alerted security companies who blocked the extensions.

The Rotbrow malware isn't problem on newer versions of Windows because security improvements in Windows 8 and 8.1 such as ASLR (Address Space Layout Randomisation) and DEP (Data Execution Prevention) mean it's harder to exploit the vulnerability and therefore attackers are less likely to spend time finding the holes and embedding malware.

However, Microsoft's Tim Rains, director of the company's Trustworthy Computing division explained that just because the platforms are harder to crack, it doesn't mean they are safe.

He said attackers are more likely to bundle malware with legitimate programs or music rather than installing it remotely onto computers using vulnerabilities in the operating system itself.