Filtering on external syslog message.keyword for SRC=aaa.bbb.ccc.ddd IP address

Elastic Observability
3

Apologies for the delay.

Here is my, very dated, logstash filter file. I see that it is setup basically for ssh metrics:
filter {
if [fileset][module] == "system" {
if [fileset][name] == "auth" {
grok {
match => { "message" => ["%{SYSLOGTIMESTAMP:[system][auth][timestamp]} %{SYSLOGHOST:[system][auth][hostname]} sshd(?:[%{POSINT:[system][auth][pid]}])?: %{DATA:[system][auth][ssh][event]} %{DATA:[system][auth][ssh][method]} for (invalid user )?%{DATA:[system][auth][user]} from %{IPORHOST:[system][auth][ssh][ip]} port %{NUMBER:[system][auth][ssh][port]} ssh2(: %{GREEDYDATA:[system][auth][ssh][signature]})?",
"%{SYSLOGTIMESTAMP:[system][auth][timestamp]} %{SYSLOGHOST:[system][auth][hostname]} sshd(?:[%{POSINT:[system][auth][pid]}])?: %{DATA:[system][auth][ssh][event]} user %{DATA:[system][auth][user]} from %{IPORHOST:[system][auth][ssh][ip]}",
"%{SYSLOGTIMESTAMP:[system][auth][timestamp]} %{SYSLOGHOST:[system][auth][hostname]} sshd(?:[%{POSINT:[system][auth][pid]}])?: Did not receive identification string from %{IPORHOST:[system][auth][ssh][dropped_ip]}",
"%{SYSLOGTIMESTAMP:[system][auth][timestamp]} %{SYSLOGHOST:[system][auth][hostname]} sudo(?:[%{POSINT:[system][auth][pid]}])?: \s*%{DATA:[system][auth][user]} :frowning: %{DATA:[system][auth][sudo][error]} ;)? TTY=%{DATA:[system][auth][sudo][tty]} ; PWD=%{DATA:[system][auth][sudo][pwd]} ; USER=%{DATA:[system][auth][sudo][user]} ; COMMAND=%{GREEDYDATA:[system][auth][sudo][command]}",
"%{SYSLOGTIMESTAMP:[system][auth][timestamp]} %{SYSLOGHOST:[system][auth][hostname]} groupadd(?:[%{POSINT:[system][auth][pid]}])?: new group: name=%{DATA:system.auth.groupadd.name}, GID=%{NUMBER:system.auth.groupadd.gid}",
"%{SYSLOGTIMESTAMP:[system][auth][timestamp]} %{SYSLOGHOST:[system][auth][hostname]} useradd(?:[%{POSINT:[system][auth][pid]}])?: new user: name=%{DATA:[system][auth][user][add][name]}, UID=%{NUMBER:[system][auth][user][add][uid]}, GID=%{NUMBER:[system][auth][user][add][gid]}, home=%{DATA:[system][auth][user][add][home]}, shell=%{DATA:[system][auth][user][add][shell]}$",
"%{SYSLOGTIMESTAMP:[system][auth][timestamp]} %{SYSLOGHOST:[system][auth][hostname]} %{DATA:[system][auth][program]}(?:[%{POSINT:[system][auth][pid]}])?: %{GREEDYMULTILINE:[system][auth][message]}"] }
pattern_definitions => {
"GREEDYMULTILINE"=> "(.|\n)"
}
remove_field => "message"
}
date {
match => [ "[system][auth][timestamp]", "MMM d HH:mm:ss", "MMM dd HH:mm:ss" ]
}
geoip {
source => "[system][auth][ssh][ip]"
target => "[system][auth][ssh][geoip]"
}
}
else if [fileset][name] == "syslog" {
grok {
match => { "message" => ["%{SYSLOGTIMESTAMP:[system][syslog][timestamp]} %{SYSLOGHOST:[system][syslog][hostname]} %{DATA:[system][syslog][program]}(?:[%{POSINT:[system][syslog][pid]}])?: %{GREEDYMULTILINE:[system][syslog][message]}"] }
pattern_definitions => { "GREEDYMULTILINE" => "(.|\n)" }
remove_field => "message"
}
date {
match => [ "[system][syslog][timestamp]", "MMM d HH:mm:ss", "MMM dd HH:mm:ss" ]
}
}
}
}

A typical kibana discovery line would be like the one below. I would like to be able to filter on internal message content for the dropped source IP's (e.g. SRC=185.156.73.60) and see how many drops and locations over a period of time. Of course, source and destination ports would be an interest as well. Hopefully I am providing the proper information.