How to prevent angler exploit kit attack on HP-UX Web server?

Dear Support,

I would like to inquire about how to prevent angler exploit kit attack on HP-UX Web server?

Our server is running on HPUX 11.31 wtih apache, the following version of Sophos Anti-Virus.  Please kindly advise. 

Sophos Anti-Virus       = 9.2.3
Threat detection engine = 3.45.0
Threat data             = 4.91
Threat count            = 5366039
Threat data release     = Wed Jul 10 00:00:00 2013

Thanks and Regards.