SSH

Secure Shell (SSH) runs on port 22, providing a secure way to access a computer remotely.

SSH can have password authentication or password-less using public-key authentication, aka an SSH public/private key pair.

SSH can be used to upload/download files from remote systems.

During attacks, clear-text credentials for an SSH private key may be found.

An SSH connection is typically more stable than a reverse shell connection, and can be used to enumerate and attack other hosts in the network, transfer tools, set up persistence, etc.

We can read local private keys on a compromised system and add our own public key to gain SSH access to a specific user.