Mac computers used by Apple Inc. employees were attacked by hackers, the company said Tuesday. Apple (NASDAQ: AAPL) said it was releasing a software update that would protect Mac users from the Java-related malware. It was a rare admission from Apple, which has long played up its computers' resistance to malicious software. The attack is thought to be the same that hit Facebook Inc. (NASDAQ: FB) computers, reported on Friday. Read more at the Wall Street Journal.