Thousands of accounts on web-based e-mail system Hotmail have been compromised in a phishing attack, software giant Microsoft has confirmed.
BBC News has seen a list of more than 10,000 e-mail accounts, predominantly originating from Europe, and passwords which were posted online.
Microsoft said it had launched an investigation.
Phishing involves using fake websites to lure people into revealing details such as bank accounts or login names.
"We are aware that some Windows Live Hotmail customers' credentials were acquired illegally and exposed on a website," said a Microsoft spokesperson.
