Fake SMTP/FTP Server Detection (possible backdoor)
Critical Nessus Plugin ID 32376
SynopsisThe remote service seems to be a backdoor
DescriptionAlthough this service answers with 3 digit ASCII codes like FTP, SMTP or NNTP servers, it sends back different codes when several NOOP commands are sent in a row.
This is probably a backdoor; in this case, your system is compromised and an attacker can control it remotely.
SolutionDisinfect or reinstall your operating system.