If you’re still playing while hackers are on the server here’s my tips:

• Despawn your loot while they’re offline (I know how hard this is but it’s the only way to prevent them from getting it 100%)
• Or, BV it temporarily
• Do not talk to them, the more you give them attention the more likely they’ll target you
• Put all of your loot if you don’t despawn or BV into locked containers
• Make sure your base is sealed 100%, as in, if you’re building on the side of something ensure it isn’t exposed to the mesh with an opening, seal it
• When you log off throw all of your kit and inventory into a locked chest
• While out and about and the hacker is online don’t go out with anything you want to lose
• Accept that they will have DP and will probably bomb your base, accept it
• I repeat, do not talk to them, do not comment in global, do not VC

Eventually BE will resolve the hack client, could take days, weeks or months. Or, they get suspended/banned but that won’t matter if they have or buy alts. Or they lose interest.