RIPE Network Coordination Centre, Denmark

I am seeing hundreds of suspicious messages in the Asterisk Log File full on a server. It is Asterisk 2.9 and is very old right now. I am working on updating our installation and am very new at this.

/var/log/asterisk/ tail -f full

Such as:
[2015-10-11 11:20:07] NOTICE[2813] chan_sip.c: Registration from ‘“9090” sip:[email protected]:5060’ failed for ‘’ - No matching peer found

They appear to own very large domain ranges.

Net Range -

Net Range -

Net Range -
They do not appear to be getting through and hacking our trunks

We were going to block these IP Ranges in our firewall. Does anyone know any negative affects this may have?

Brief searches show other folks have had RIPE associated with hacking. Has anyone else experienced anything like this?

Thanks in advance if you can help.

Does not seem to be a threatening organization