How do I know if theme downloads are safe or have a backdoor etc.?

Stick to downloading themes from www.remarpro.com. All themes hosted here have undergone an extensive review that should eliminate these kinds of problems.

Thanks Esmi. the theme we like is from Theme Blvd. would that be OK as far as you know?

I’m sorry but we couldn’t really comment on themes from other sources.

OK understood. Is there a trick or way you know of that I can check?

There’s no “trick” involved. You have to actually review the theme’s code.

o dear… Not my skill.

Thanks.