Molly, a skilled hacker, opted to target an organization's network. In executing her attack, she employed a tool to transmit deceptive ARP messages across the target network, associating her MAC address with the IP address of the victim's system. Through this manipulation, Molly intercepted messages directed to the victim's MAC address and subsequently utilized the tool to capture, alter, and obstruct sensitive communications to the targeted system. What tool did Molly use to execute the described attack?