An update for a Kaspersky anti-virus product knocked thousands of Windows XP users offline, and even blocked some users from accessing internal company networks. Kaspersky became aware of the issue very quickly and had a fix at hand within two hours.
As a workaround at first Kaspersky said affected users needed to disable the product or roll back the update.
The Russian security firm then issued a statement, apologizing for any inconvenience caused by the database update error.
From users' reports of the problem, it would appear that the update altered the database to block access to port 80, the default port used by web servers to listen for client (browser) requests.
Oops.
Written by: James Delahunty @ 6 Feb 2013 10:56
