Nessus and Splunk accessing Oracle DB servers

We are noticing a lot of listener misconnections in a particular bracket of time each week (over about 6 hours), and was wondering if Nessus or Splunk may be contributing to this.

Do they also possibly contribute to memory usage?

We had a spate of listener events over the weekend for one particular server for a period of about 15 mins.  Later this server had memory issues.  The Host was a Nessus server.

06-APR-2019 05:13:43 * http * (ADDRESS=(PROTOCOL=tcps)(HOST=xxxx)(PORT=yyyy)) * handoff * http * 0

06-APR-2019 05:13:43 * http * (ADDRESS=(PROTOCOL=tcps)(HOST=xxxx)(PORT=zzzzz)) * handoff * http * 0

We are a Windows shop, using Win2008/2012 servers, Oracle9 through to Oracle12.2.