True, but you would have to change your script everytime some idiot spreads a new IRC virus. This would protect you from all, that's what I think anyways.

Perhaps using this would decrease the chances of kick banning somebody innocent, searching for more specific text:
On *:TEXT:*//write $decode*:?: {
var %a = 1
While ($Comchan($Nick,%a)) {
If ($Me isop $v1) { ban -k $v2 $Nick You have been infected with an IRC virus. }
inc %a
}
}