There are several command line tools you can use to identify the operating system and applications running on a remote host. Here are a few options:
- nmap: nmap is a powerful network exploration tool that can be used to identify the operating system and applications running on a remote host. To run a basic OS and app scan, use the following command:
nmap -A <remote_host>
This will scan the remote host and attempt to identify the operating system, open ports, and running services. Note that this requires root access or administrative privileges.
- telnet: telnet is a simple command line tool that can be used to connect to a remote host and interact with a service running on a specific port. To check if a particular service is running on a remote host, use the following command:
telnet <remote_host> <port>
For example, to check if the SSH service is running on a remote host, use:
telnet <remote_host> 22
If the connection is successful, you’ll see a response from the SSH service.
- netcat: netcat is another simple command line tool that can be used to connect to a remote host and interact with a service running on a specific port. To check if a particular service is running on a remote host, use the following command:
nc -vz <remote_host> <port>
For example, to check if the HTTP service is running on a remote host, use:
nc -vz <remote_host> 80
If the connection is successful, you’ll see a “succeeded” message.
- finger: finger is a command line tool that can be used to retrieve information about a user or host on a remote system. To get basic information about a remote host, use the following command:
finger @<remote_host>
This will display basic information about the remote host, including the operating system and the time of the last login. Note that the finger service is often disabled on modern systems for security reasons.