Original URL: http://www.theregister.co.uk/2013/02/06/kaspersky_win_xp_update_snafu/

Antivirus update broke our interwebs, howl Win XP users

You were only supposed to blow the bloody viruses off

By John Leyden

Posted in Security, 6th February 2013 16:19 GMT

Updated Thousands of Windows XP users were blocked from accessing the internet this week after they applied a misfiring antivirus update from Kaspersky Lab.

The issue affected both consumer and business versions of Windows XP. Vista or Windows 7 users were untouched by the snafu.

Even so, Kaspersky's support forums quickly filled up with complaints from frustrated users and hassled sysadmins.

The Russian anti-virus firm said the problem could be resolved if users disabled the "Web AV" component of the software before rolling back problematic update and installing a revised set of virus definition files, which was published within two hours of the problem rearing its ugly head late on Monday. The "Web AV" component can be reapplied once this process is completed.

This is all fairly straightforward, providing you can get online and access these instructions. Misfiring antivirus updates affect all vendors from time to time. Even though quality assurance processes have improved across the industry, the odd bad update still gets through.

The issue is at its most problematic when antivirus components start identifying core operating system components as potentially malign, carrying them off into quarantine and leaving users with machines that won't run or boot up again properly in the process. The dodgy Kaspersky update wasn't quite as bad as that, but still posed a major inconvenience for those affected. ®

Update

Kaspersky's since been in touch to say:

Kaspersky Lab would like to apologise for any inconvenience caused by this database update error. Actions have been taken to prevent such incidents from occurring in the future.

It added:

The problem only affected x86 systems with the following products installed: Kaspersky Anti-Virus for Windows Workstations 6.04 MP4; Kaspersky Endpoint Security 8 for Windows; Kaspersky Endpoint Security 10 for Windows; Kaspersky Internet Security 2012 and 2013; and Kaspersky Pure 2.0.