Can anyone help ID this please?

[Mac1330]

Hi guys I was just wondering if anyone can help tell me what this is on my live rock? It's just on one rock at the moment but if it's not good I don't want it to spread? It's like waxy and soft?

Any help is much appreciated thanks.

 

[Tahoe61]

Sponge, sometimes called Liver Sponge, it can become invasive.

 

[Mac1330]

Thanks Tahoe, Any advice on what to do with it? Don't wanna scrape it if it means it's going to spread more.