Hello,
our site has been hacked by Hmei7. We used a security fix patch right after recieving your newsletter on Jomsocial 2.6.

This is from server log:
200.91.218.190 - - [08/Feb/2014:20:21:31 +0100] "GET /index.php?option=com_community&view=frontpage&jampiro=140208-141524 HTTP/1.1" 200 109334 "-" "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.9) Gecko/20100824 Firefox/3.6.9"

200.91.218.190 - - [08/Feb/2014:20:21:33 +0100] "POST /index.php?jampiro=140208-141527 HTTP/1.1" 200 - "-" "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.9) Gecko/20100824 Firefox/3.6.9"

200.91.218.190 - - [08/Feb/2014:20:21:34 +0100] "GET /x.php?lwckaj&jampiro=140208-141528 HTTP/1.1" 200 418 "-" "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.9) Gecko/20100824 Firefox/3.6.9"

...any suggestions about this,

Thank you,
Pavel

Hello, the hacker must have placed a backdoor before you even added the patch. You must check all your files, find the backdoor and remove it.