Maiko,
I see mostly HTTP (tcp/80) RDP (tcp/3389), Telnet (tcp/23), DNS (udp/53)
and ping (ICMP type 8), just common port scans on the net. Mostly
Advansed Persistent Threat gangs looking for vunerable machines via
already compromised devices. They've been prevalent on the Internet
since Mandiant exposed the ongoing "cyberwar."
N1URO is correct, HTTPS probing was probably started when Heartbleed was
announced...
...if you have records of connections before it was made public on April
8th (as I recall), that information may be useful...you may have
discovered someone who knew/exploited the HTTPS/OpenSSL threat pre zero-day.
-KB3VWG