A little bit more (warning: a few of these are related to Intel ME hardware, not Intel AMT firmware):
Rumor has it that OpenAMT can also be used for AMT detection:
https://sourceforge.net/p/openamt/wiki/Home/
AMT advisory from ASUS:
https://www.asus.com/News/uztEkib4zFMHCn5r
http://blog.trendmicro.com/tippingpoint-threat-intelligence-zero-day-coverage-week-may-8-2017/
http://www.govinfosecurity.com/intels-amt-flaw-worse-than-feared-a-9901
Is Intel’s Management Engine Broken?
https://twitter.com/4Dgifts/status/862326241659150336