Thanks for the response guys. I actually wanted to suggest hiring experts for my boss since the problem has persisted for more than 2 weeks already.  But I needed to be sure it would be a logical choice considering I have no programming background and I wanted to make sure I would not be undermining our IT guy. 

Just a newbie here and I am hoping that the security geniuses in here can help us with a problem. I am not a programmer, but our IT person seems to have problems removing malicious codes/scripts in our system. (Hope this is the right thread).

I work for an online shop which has several programs interfaced with the live site. A month ago, we started having problems with the database. New entries or updates on the database are methodically deleted after an hour or so and even images are being deleted.

My boss tells me that they found about 5 of the malicious codes in several applications and thought that they had cleaned it. When we started working again on the database, the same thing started happening again.

Would appreciate any idea that can help us nip the problem in the bud.

Thanks.