Microsoft CEO Satya Nadella Microsoft Microsoft is trying to solve the issue of "insider spoofing" in emails, according to a company blog post.

The practice, where an outsider pretend to be a CEO or another executive to extort money, has cost businesses around $750 million (£530 million) between October 2013 and August 2015, according to the FBI.

Microsoft has updated Outlook, its email client, to detect outsiders and fraudsters and has had some success. According to Microsoft, the company has seen a 500% improvement in counterfeit detection.

The company is rolling out a new way of identifying legitimate emails and is working on detecting malware faster before alerting businesses.

Microsoft CEO Satya Nadella made a big deal out of the new features at a conference in Washington, D.C. last month, speaking about the new "sandboxing" of suspicious files. However, cordoning off files for analysis takes time, and this is something Microsoft is working on improving.

Microsoft has increased the amount it spends on security, positioning itself as a champion of businesses both in terms of privacy — especially against government requests — and day-to-day attacks on computers. Nadella told The New York Times that Microsoft had hired around 20% more employees to deal with security threats in 2015.