I would guarantee it performs evasive manoeuvres in its terminal phase to make hitting it with cannon fire near impossible. GRANIT, MOSKIT, ONYX, YAKHONT, BRAHMOS all do it too.
When the incoming missile is moving at 800m/s+ then the aim point is going to be well in front of it. If Phalanx starts engaging at its max effective range of 1.6km then the projectile flight time to that distance will be about 1.5 seconds, which means the missile itself will be (assuming 800m/s of the target) 1.2km + 1.6km away, or 2.8km from the ship. The phalanx will start firing and its first rounds from its burst will arrive 1.6km from the ship, so the incoming missile has travelled 1.2km before the first rounds have a chance of hitting it. A few up and down manouvers of 10 degrees or so from 3km from the ship will result in that initial burst going too high or into the sea because a 10 degree climb over 1.2km will be dozens of metres above the level flight altitude of the missile... if it only climbs for 600m and then starts to dive and turn to one side then not only the first burst will miss by dozens of metres but the instant correction will also lead the Phalanx to overcorrect and spray wildly.
These manouvers are not 90 degree turns and will not slow the missile too much so that Phalanx still gets maybe 100 rounds to hit the target before impact and it hasn't started well. Even a random corkscrew manouver will lead to a small fraction of the possible hits actually hitting the target.
Those rounds that do hit will have to deal with lightweight Ti armour protecting the warhead.
My money is on the Yakhont... and the US Navy replacing the Phalanx with SEA RAM suggest they agree with me.
Onyx is the missile the Russians use, Yakhont is the range and warhead limited export model. Brahmos has an enormous electronic and sensor upgrade to add land attack capability in addition to being able to hit sea targets.
The Onyx is a long range Yakhont with nuclear warhead options.
This system is the land based truck launched Yakhont but it comes in lots of versions including surface and subsurface and air launched models.
Yakhont is anti ship only and has no land attack capability (like Onyx).
Converting it to land attack capability would be like converting an AMRAAM to anti tank use... ie all new guidance and warhead fusing etc etc.
The Indians wanted a missile to attack land targets and they spent quite a bit of money and got the makers of the Yakhont to help them. If India couldn't do it alone then I rather doubt the Syrians could.
Of course as you mention the Israelis are in one breath upset at the sale of a banana, and in the other breath they will say that it is OK because they have a defence against Bananas and will share this defence to render Russian Bananas useless.
Russian Bananas are only cheap and simple copies of much better American bananas anyway because Russia has no intelligent people... or something like that.
Forget Yakhonts... how many shipping containers are heading to Syria too!!!!