Overview of services running on Port 50021 TCP.
~6 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	Version	Info	OS	Devicetype	Count	Percent
chat	AIM or ICQ server					1711	26.258
no match						1649	25.307
http	lighttpd	1.4.19				359	5.51
http						331	5.08
ftp						244	3.745
http	Microsoft IIS httpd					134	2.056
ftp	DrayTek Vigor 2820 ADSL router ftpd	1.0			broadband router	125	1.918
ftp	Microsoft ftpd			Windows		118	1.811
http	Microsoft HTTPAPI httpd	2.0	SSDP/UPnP	Windows		113	1.734
ssh			protocol 1.5			80	1.228
mongodb	MongoDB	23				78	1.197
ftp	Pure-FTPd					61	0.936
ftp	vsftpd	2.0.5		Unix		55	0.844
telnet						48	0.737
ftp	MikroTik router ftpd	3.30			router	44	0.675
ftp	FileZilla ftpd	0.9.41 beta		Windows		43	0.66
vnc	VNC		protocol 3.8			42	0.645
http	thttpd					42	0.645
ftp	vsftpd	2.2.2		Unix		39	0.599
ftp	ProFTPD	1.3.3		Unix		35	0.537
http	WangWnagSimpleServer	1.0				32	0.491
ftp	vsftpd	2.0.7		Unix		28	0.43
ftp	MikroTik router ftpd	5.6			router	27	0.414
ftp	FileZilla ftpd	0.9.37 beta		Windows		26	0.399
ftp	Serv-U ftpd	6.4		Windows		25	0.384
http	Boa HTTPd	0.94.14rc21				22	0.338
ftp	Synology DiskStation NAS ftpd				storage-misc	20	0.307
ftp	ProFTPD	1.3.3a		Unix		20	0.307
ftp	FileZilla ftpd	0.9.40 beta		Windows		20	0.307