– Microsoft spokesman Matt Thomlinson
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.
We have no evidence of customer data being affected and our investigation is ongoing.
This type of cyberattack is no surprise to Microsoft and other companies that must grapple with determined and persistent adversaries.
Microsoft has said it is investigating the hacking of a small number of its computers - a breach which it said was "similar" to security intrusions recently reported by Apple Inc and Facebook.
Microsoft Corp, the world's largest software company, said the computers targeted with malware included some in its Mac software business unit, Reuters has reported.
The firm said there was no evidence customer data had been affected.
Apple is trying to identify the source of vicious malware attacks on a "limited number" of its Mac systems, a statement from the corporation said.
The corporation is to release new updated software to protect users and its systems.
Apple has identified malware which infected a limited number of Mac systems through a vulnerability in the Java plug-in for browsers.
The malware was employed in an attack against Apple and other companies, and was spread through a website for software developers.
We identified a small number of systems within Apple that were infected and isolated them from our network.
There is no evidence that any data left Apple.
We are working closely with law enforcement to find the source of the malware.
Since OS X Lion, Macs have shipped without Java installed, and as an added security measure OS X automatically disables Java if it has been unused for 35 days.
To protect Mac users that have installed Java, today we are releasing an updated Java malware removal tool that will check Mac systems and remove this malware if found.
Apple has revealed it has been targeted by computer hackers and will today release a software tool to protect customers against malicious software used in attacks.
The corporation says that there is "no evidence that any data left Apple" and that it is working with law enforcement personnel to identify hackers.
Facebook and other companies have also been targeted, according to Reuters.