The rule detects the use of the Point-to-Point Tunneling Protocol (PPTP), a VPN technology that is increasingly exploited by threat actors to conceal their network traffic and facilitate malicious activities. It checks for network events categorized as 'network' or 'network_traffic' and specifically looks for TCP traffic directed at port 1723, which is the standard port used by PPTP connections. Although PPTP may not be commonly used in modern networks, its activity may indicate suspicious tunneling behavior. It's important to note that some legitimate services could inadvertently trigger this rule, leading to false positives, especially if an application server responds to TCP connections on this ephemeral port.