The rule is matching VPN logon failure events where the Source Country is outside the configured home country . In the exhibit, the filter section shows Event Type IN EventTypes: VPN Logon Failure and Source Country NOT IN GeoCountries: My Home . That means the source must be outside the home-country geo group. The aggregate condition shows COUNT(Matched Events) > = 3 , so the rule is looking for at least three matching failed VPN logon events. The Group By section uses Source IP and User , so FortiSIEM evaluates the count per unique source IP and user combination, not by different countries.

The FortiSIEM Study Guide explains that a rule subpattern contains three components: Filter , Aggregate , and Group By . It states that the filter identifies the matching event group, the aggregate function specifies how many events must match, and Group By combines events with the same grouped attributes into one row while the count tracks those events.

Option A is wrong because the rule does not count different countries. Options C and D are wrong because the source country is explicitly NOT IN My Home, not inside the home country.