Which command can help determine whether the Tor browser was used on the suspected machine?

The command that can help determine whether the Tor browser was used on the suspected machine is netstat -ano. This command displays the active network connections on the device, including the local and remote IP addresses, the status of those connections, and the process IDs (PID) associated with them. When the Tor browser is active, it establishes network connections to Tor network nodes, which can be identified through the output of this command. By analyzing the established connections, a forensic investigator can recognize whether there are any connections related to Tor, indicating that the Tor browser was indeed used.

In contrast, the other commands serve different purposes and do not provide the necessary insight into network connections relevant to the Tor browser. The ps aux command lists running processes on a system, which may show Tor as a process but lacks details about network activity. The tracert command traces the route that packets take to a specified IP address and does not provide information about active connections or applications in use. The ipconfig command displays the network configuration of the machine but does not reveal information about active connections or the applications that are using them. Therefore, netstat -ano is the most appropriate choice for identifying usage of the Tor browser.