Database admins are warned to bolt up the security of their Microsoft SQL Servers after the discovery of a worm which infects machines with default passwords.

The Spida worm attempts to locate and login to Microsoft SQL Servers with the default SQL administrator account, "SA", and a blank password. SQL Server ships with this by default and if you've haven't got around to securing it properly, now would be a good time to do so.

Although the Spida worm is not destructive to the infected host (aside from attempting to mail out its configuration), it may generate a damaging level of network traffic when it scans for additional targets. Spida comes with a multi-threaded scanner that searches both internal and external IP addresses for vulnerable servers.

Security tools vendor ISS reports that the worm is responsible for "large amounts of Internet traffic as well as millions of TCP/IP probes".

ISS advises that sysadmins should block port 1433 TCP traffic at the perimeter while ensuring that SQL servers have an administrative account properly secured and patched. Antivirus vendors are currently updating their definitions to pick up the exploit.

Microsoft's advice on securing SQL Server can be found among the documents here. ®