An AT&T Samsung Galaxy S7 might have been the initial access point into the DNC network.
Mueller Report (PG 38)
Hack used: SM-2589105-HACK
SM-DevCode-Model-Series-Rev
DevCodes: G-Galaxy, T-Tablet
DC 25=2+5=7=G
Series: 0=A
SM-G-891-A-5
SM-G891A-rev5 = ATT Samsung Phone Model.
http://support-us.samsung.com/cyber/findmodel.jsp
https://www.sammobile.com/devices/galaxy-s7-active-att/specs/SM-G891A/