From the Manual for MariaDB (https://mariadb.com/kb/en/library/activating-the-binary-log/)
If you don't provide a name (which can, optionally, include an
absolute path), the default will be datadir/log-basename-bin,
datadir/mysql-bin or datadir/mariadb-bin
Clients with the SUPER privilege can disable and re-enable the binary
log for the current session by setting the sql_log_bin variable.
SET sql_log_bin = 0;
SET sql_log_bin = 1;
However, if you say it was enabled by default during installation, you must disable by removing the line from your my.cnf file and then restart mysqld. You can also purge the binary data (https://dev.mysql.com/doc/refman/5.6/en/purge-binary-logs.html)
PURGE BINARY LOGS
Finally, as the other poster's answer mentions, in MySQL 8 there is an option to explicitly turn off binary logging from the configuration file using the
--disable-log-bin options in the [mysqld] section of the config file.
To disable binary logging, you can specify the
--disable-log-bin option at startup. If either of these options is specified and
--log-bin is also specified, the option specified later
takes precedence. When binary logging is disabled, the log_bin system
variable is set to OFF.