I second this, snare format is parsed by FortiSIEM, so you can tell nxlog to send in that format.
Replace your nxlog.conf file with this one, and then restart the nxlog service. Also specify your log target of the collector instead of 1.1.1.1
Panic Soft
#NoFreeOnExit TRUE
define ROOT C:\Program Files (x86)\nxlog
define CERTDIR %ROOT%\cert
define CONFDIR %ROOT%\conf
define LOGDIR %ROOT%\data
define LOGFILE %LOGDIR%\nxlog.log
define OUTPUT_DESTINATION_ADDRESS 1.1.1.1
define OUTPUT_DESTINATION_PORT 514
LogFile %LOGFILE%
Moduledir %ROOT%\modules
CacheDir %ROOT%\data
Pidfile %ROOT%\data\nxlog.pid
SpoolDir %ROOT%\data
<Extension _syslog>
Module xm_syslog
</Extension>
<Extension _charconv>
Module xm_charconv
AutodetectCharsets iso8859-2, utf-8, utf-16, utf-32
</Extension>
<Extension _exec>
Module xm_exec
</Extension>
<Extension _fileop>
Module xm_fileop
# Check the size of our log file hourly, rotate if larger than 5MB
<Schedule>
Every 1 hour
Exec if (file_exists('%LOGFILE%') and \
(file_size('%LOGFILE%') >= 5M)) \
file_cycle('%LOGFILE%', 8);
</Schedule>
# Rotate our log file every week on Sunday at midnight
<Schedule>
When @weekly
Exec if file_exists('%LOGFILE%') file_cycle('%LOGFILE%', 8);
</Schedule>
</Extension>
<Extension json>
Module xm_json
</Extension>
<Input internal>
Module im_internal
</Input>
<Input eventlog>
Module im_msvistalog
Query <QueryList>\
<Query Id="0">\
<Select Path="Application">*</Select>\
<Select Path="System">*</Select>\
<Select Path="Security">*</Select>\
</Query>\
</QueryList>
Exec if ($EventID == 5156) OR ($EventID == 5158) drop();
Exec $HOSTNAME=hostname();
Exec $Message =~ s/(\t|\R)/ /g;
</Input>
<Output out>
Module om_udp
Host %OUTPUT_DESTINATION_ADDRESS%
Port %OUTPUT_DESTINATION_PORT%
Exec to_syslog_snare();
</Output>
<Route 1>
Path eventlog, internal => out
</Route>