A network traffic analyzer (also known as a packet sniffer) is the best tool to identify credentials being transmitted in plaintext, such as those used in Telnet sessions. Since Telnet transmits data without encryption, a network traffic analyzer can capture the traffic between the client and the network switches, revealing sensitive information, including login credentials, in clear text. This tool helps identify insecure protocols and enables remediation by switching to encrypted alternatives like SSH.

https://www.kaspersky.com/resource-center/threats/what-is-a-honeypot

Filter XYZ is the best option that meets the budget needs of the business. Filter XYZ has an ALE of $1 million per year, which is lower than any other filter option. ALE stands for annualized loss expectancy, which is a measure of how much money a business can expect to lose due to a risk over a year. ALE is calculated by multiplying the annualized rate of occurrence (ARO) of an event by the single loss expectancy (SLE) of an event. ARO is how often an event is expected to occur in a year. SLE is how much money an event will cost each time it occurs. Therefore, ALE = ARO x SLE. Filter XYZ has an ARO of 0.1 and an SLE of $10 million, so ALE = 0.1 x $10 million = $1 million.