Taking an inventory of the compromised machine for privilege escalation, a tcpdump pcap was run passively for about an hour. Multiple protocols should be added to this one-liner depending on the environment. Here are some useful services commonly sniffed:
http/s, smb, dns, smtp, pop3, imap, ftp, snmp. A TCP wildcard could be used but be wary of filesizes, especially when operating on a foothold. Filtering is used to target exploitable use cases as well as prevent large pcaps from accumulating and effecting operability of the machine.