If I were you, I would be suspicious as well. Let's break this down in a logical perspective to help your thoughts.

1) All you found were a few little ads tied to some recruitment thing - shows they are either low budgets or new. These are both warning flags, low budget usually means cheating you out of benefits/late payments and new means inexperienced. That means BIG HEADACHES for you.

2) You said they were urgent to get you there. Well that could mean that their previous ESL teacher ran off, they are just opening and are highly unorganized, or they don't want to give you time to research and think about this position so they can trap you before you get wise. Sounds like another red flag!

3) I have seen many Korean posts and this one to me is unfamiliar, which lends support to my "they are new" theory. It also sounds like a training center which is a BIG NO-NO! That in itself is always a HUGE red flag.

So if I were you, I wouldn't take my chances and I would look for a more reputable establishment. There are tons of schools in Korea, research until one doesn't leave you feeling like you are walking into a slaughter house.

Hope that help,

NGET! :)