Brown spreading patch on sinularia

[Shazbop07]

Hi. I noticed brown patch on this sinularia 3 days ago. Moved a hammer close by. It's got bigger though. Does this look like a sting? TIA

 

[fishguy242]

not sure but dip and clean off ,i also see black tip on branch ,phead or turkey baster ,or cut off

 

[Shazbop07]

Thanks. It's stuck fast to the rock so i can't dip it or I would. I'll cut off the other black bit though