Back in 2022, however, an RFI had been released calling for input for a new Close Combat Missile System-Heavy (CCMS-H) which would “initially augment existing stockpiles of the TOW Family of Missiles,” with the new weapon required to be compatible with existing TOW platforms and launchers.
CCMS-H was required to defeat 'Tier 1' armoured targets equipped with soft and hard-kill defences, dual-command guidance and the ability to incorporate reprogrammable target prioritization, to enable semi-simultaneous engagements of multiple threats at distances of minimum 65 meters and direct, 4500 meters and beyond. With a cooperative engagement with cross-cueing between different platforms, the missile should be lethal out to 8000 meters, with its parabolic trajectory keeping below 3000 feet of altitude.
Also in 2022, experimental launches were observed of 'Ground Launch Effects', or GLE, a large drone-missile, fired from TOW launchers, optically-tracked, wire-guided which could loiter, providing intelligence, surveillance and reconnaissance, before striking. The GLE, a large tubular drone with prominent fold-out wings, was made by Raytheon.
'670' is very possibly a continuation, more or less direct, of those efforts.