Microsoft confirms it was recently targeted by hackers in a cyber attack similar to those which affected Facebook and Apple.
Microsoft has become the latest victim of computer hacking following US technology giants Facebook and Apple.
In a blog posting, Microsoft said it had found no evidence that any customer data had been stolen in the cyber attack, which saw malicious software planted on a small number of its computers.
General manager Matt Thomlinson said: "As reported by Facebook and Apple, Microsoft can confirm that we also recently experienced a similar security intrusion.
"During our investigation, we found a small number of computers, including some in our Mac business unit, that were infected by malicious software using techniques similar to those documented by other organisations."
Microsoft gave few other details about the break-in, except to say that was it similar to a hacking attack that online social networking leader Facebook disclosed last week.
Facebook said malware that infected some of its machines came from a mobile developer website that had been booby-trapped.
A "small number" of computer systems at Apple were infected but they were isolated from the main network and there was no evidence that any data left Apple, the company said.
Online messaging service Twitter also recently disclosed that hackers may have stolen information about 250,000 of its users.