Find sigma rule 
Attack: Remote Services: SSH
Adversaries may use Valid Accounts to log into remote machines using Secure Shell (SSH). The adversary may then perform actions as the logged-on user.
SSH is a protocol that allows authorized users to open remote shells on other computers. Many Linux and macOS versions come with SSH installed by default, although typically disabled until the user enables it. The SSH server can be configured to use standard password authentication or public-private keypairs in lieu of or in addition to a password. In this authentication scenario, the user’s public key must be in a special file on the computer running the server that lists which keypairs are allowed to login as that user.
MITRE
Tactic
- lateral-movement
technique
- T1021.004
Test : ESXi - Enable SSH via PowerCLI
OS
- linux
Description:
An adversary enables the SSH service on a ESXi host to maintain persistent access to the host and to carryout subsequent operations.
Executor
powershell