Overview of services running on Port 523 TCP.
~29 Thousand IP addresses observed from May to December 2012
To get raw lists of the data go to Download. For an explanation of what this data is and how it was obtained, see Paper.

Servicename	Product	Count	Percent
telnet	USRobotics/Sagem router telnetd	10666	36.307
telnet	Netgear broadband router or ZyXel VoIP adapter telnetd	9623	32.757
ibm-db2	IBM DB2 Database Server	2658	9.048
chat	AIM or ICQ server	2193	7.465
no match	-/-	1642	5.589
http	lighttpd	407	1.385
socks5		369	1.256
http		356	1.212
http	Microsoft IIS httpd	198	0.674
ssh	OpenSSH	157	0.534
http	Microsoft HTTPAPI httpd	134	0.456
http	thttpd	132	0.449
ssh		96	0.327
telnet		61	0.208
vnc	VNC	56	0.191
http	Boa HTTPd	45	0.153
arcserve	ARCserve Discovery	43	0.146
mysql	MySQL	26	0.089
ftp	Microsoft ftpd	26	0.089
ftp		26	0.089
http	nginx	24	0.082
smtp	Microsoft ESMTP	21	0.071
telnet	Draytek Vigor ADSL router telnetd	18	0.061
sip		18	0.061
ftp	ProFTPD	17	0.058
ftp	FileZilla ftpd	15	0.051
ftp	Serv-U ftpd	14	0.048
smtp		13	0.044
ftp	Pure-FTPd	13	0.044
vnc	RealVNC Enterprise	11	0.037
smtp	Exim smtpd	11	0.037
ftp	vsftpd	11	0.037
telnet	Allied Telesis x900-series switch telnetd	10	0.034
ssl	TLS	10	0.034
smtp	Microsoft Exchange smtpd	10	0.034
smtp	MailEnable smptd	10	0.034