The P-120 Malakhit (Russian: П-120 «Малахит» 'Malachite'; NATO reporting name: SS-N-9 Siren, GRAU designation: 4K85[1]) is a Soviet medium range anti-ship missile used by corvettes and submarines.

The Echo-class submarine was required to spend 30 minutes or more on the surface when firing its P-5 Pyatyorka (SS-N-3A 'Shaddock') missiles.

The L band seeker and radar altimeter originally designed for the 'Siren' were first used on the 'Starbright' whilst the Soviets sorted out the P-120's troublesome engines.

However the 'Siren' has space for datalink equipment, allowing mid-course guidance from the launch platform or something else.

When fired from a submarine, the missile can be launched at a maximum depth of 50 meters.