<configuration>
<system.webServer>
<rewrite>
<rules>
<rule name="Block SomeRobot"
stopProcessing="true">
<match url="(.*)" />
<conditions logicalGrouping="MatchAny">
<add input="{REMOTE_ADDR}" pattern="x.x.x.x"
/>
</conditions>
<action type="AbortRequest" />
</rule>
</rules>