hi, its basically a chord with a long release and glide/portamento to slide between the different keys. the oscillators are probably saw waves.
easy to do in ableton with the chord midi plug. choose the 'house to go preset' & apply the portamento/glide/legato (its called different things in different plugs etc). If the sound is not rich enough you could use a bus to mix in some chorus or add/detune the oscillators in the synth etc.
you could also sample a chord and apply portamento in a sampler - which will give it a slightly different vibe when it hits that higher note/s at the end of the sound you posted.