As reported by Facebook and Apple, Microsoft can confirm that we also recently experienced a similar security intrusion.
Consistent with our security response practices, we chose not to make a statement during the initial information gathering process. 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 organizations. We have no evidence of customer data being affected and our investigation is ongoing. Microsoft Says It Too Was Hit By Recent Security Intrusion [blogs.technet.com]