Botnet attack via Alfresco Share

Hi All

We setup Alfresco Community 5.0.d on a cloud server for testing purposes. We were notified by the cloud provider that our server was causing botnet attacks. Indeed we found the attached lines in the tomcat/logs/catalina.out file.

Has anyone seen this before? We are trying to figure out how this attack might have happened and how the botnet scripts came into our system. We also haven't yet figured out which files exactly in Alfresco Share were affected.

Any pointers will be greatly appreciated.

Thanks in advance
Vipul