Security teams focus on modern stacks while old systems run unchecked. The Sleepwalker exploit shows how even obscure protocols can be dangerous.
Build a scanner that fingerprints legacy protocols (CORBA, DCOM etc) and maps potential attack surfaces with remediation steps.
Sell to enterprise security teams as part of vulnerability management.
Start with the 10 most common abandoned enterprise protocols.
Risk: May require deep reverse engineering of old specs.