Well the most obvious thing is that the strings do not reach out into higher frequencies. So either using the right waveform or filter settings will give you a good start. Also the strings are two sounds in my opinion, the higher one goes higher as the lower (more bass-y) goes lower in the progression, so you need to keep that in mind. It has longer release, which makes it overlap itself, there's also probably some lfo modulation (maybe for velocity?) with speed that alternates, or it's phasing (but I don't really think it actually is phasing) or it's just the effect of unison. The waveform could be from a wavetable plugin, but I can't really tell, though the harmonics aren't very even. Maybe the the lower one is a saw that has a stable low pass (no keytracking) with a sine wave that is one octave lower to provide bass, but I'm just speculating. I'm pretty sure you could get this sound if you were to use serum, it's just a very capable and flexible plugin. Also definitely use unison for this one, play around with it. Also, of course use a nice reverb, but that's probably very obvious. And lastly maybe chorus can help you to achieve this sound. Overal though your best bet is to look at this sound in spectrum analyzer and spectogram and see what the harmonic information is and use that (and your ears of course) as a guide.
Maybe some HG Fortune's plugins could have some wavetables that could sound alike, or any wave-table plugin. Honestly I think you could achieve this in many substantive synths like Sytrus, or additive like Harmor, all you need is an option to manipulate the oscillator more precisely. But it's definitely all about having the right wave form, separating each sound into it's correct frequency range, using correct spatial tools (unison, chorus, reverb and etc. (also the lower frequencies could benefit from being more mono)) and just tweaking it a lot.