Below are great websites which also analyse exploit kits, malware and malspam:

http://www.broadanalysis.com/
https://malwarebreakdown.com/
http://www.malware-traffic-analysis.net

Nice article about Rig EK:

https://www.uperesia.com/analyzing-rig-exploit-kit

Article by researcher Kafeine about Rig EK and other interesting posts:

http://malware.dontneedcoffee.com/2016/10/rig-evolves-neutrino-waves-goodbye.html