Microsoft has admitted that hackers were able to penetrate its South Korean MSN Web portal this week. However, the company has been quick to point out that it knew of no impact on users of the site. The company has declined to comment on whether this was an attempt to steal passwords.

"Microsoft learned of a criminal attempt to compromise an MSN Korea property hosted by a third party," MSN director Adam Sohn said in a statement.

"Upon notification of the criminal activity, the Microsoft Security Response Center and MSN response teams immediately mobilized to investigate the incident. Within a few hours of such notification, Microsoft took the appropriate action to resolve the issue and stop any additional criminal activity."

The company is continuing its investigation into these matters, and is co-ordinating with law enforcement agencies.