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Kaspersky blacklist to keyfile often do these, it is because many use the same Key Files simultaneously when the update online. So if you have been hit by Kaspersky blacklist should be to replace and update the new keyfile.
For how to replace and update can be seen on the post Tips If in Blacklist Kaspersky Update and specifically for Kasperksy 2010 on post Turn Kaspersky Anti Virus 2010 Using Key Files
INFO: Key File Kaspersky 2009 can be used also for Kaspersky 2010, and vice versa.
Download : Key File KIS 2010 and 2009
Download : Key File KAV 2010 and 2009