malicious files detected on web hosting

[santbir]

hi there,

I am using multidomain web hosting and I have hosted more than 10 websites. but only abantecart made website infected with malware name : SiteLock-PHP-EVAL_REQUEST-avxt.UNOFFICIAL but my concern is my other websites are running fine on same web hosting. Only abantecart made websites is infected everytime after cleaning those malicious files manually. I am using clam antivirus to scan all files and deleting them after I found them. But malicious files coming back again. I am tired now. Please can you guys give me solution. I think there must be a backdoor. hacker is trying XSS cross site scripting on my hosting and injecting malicious code. I can provide my site access log to you guys.

please help   

[abantecart]

What is a version of your AbanteCart? Can you post more details about attack? You can find details in the server log or error log.

[eCommerce Core]

Welcome to AbanteCart.

We need AbanteCart version.
What makes you think that your site is attacked via AbanteCart?
Possibility that you have directories/files writable for the web under abantecart, but attack can be done from any other software.

Details will clarify this mistery. Check the logs.