## Block SQL injections
set $block_sql_injections 0;
if ($query_string ~ "union.*select.*\(") {
set $block_sql_injections 1;
}
if ($query_string ~ "union.*all.*select.*") {
set $block_sql_injections 1;
}
if ($query_string ~ "concat.*\(") {
set $block_sql_injections 1;
}
if ($block_sql_injections = 1) {
return 500;
}

## Block file injections
set $block_file_injections 0;
if ($query_string ~ "[a-zA-Z0-9_]=http://") {
set $block_file_injections 1;
}
if ($query_string ~ "[a-zA-Z0-9_]=(\.\.//?)+") {
set $block_file_injections 1;
}
if ($query_string ~ "[a-zA-Z0-9_]=/([a-z0-9_.]//?)+") {
set $block_file_injections 1;
}
if ($block_file_injections = 1) {
return 500;
}

## Block common exploits
set $block_common_exploits 0;
if ($query_string ~ "(<|%3C).*script.*(>|%3E)") {
set $block_common_exploits 1;
}
if ($query_string ~ "GLOBALS(=|\[|\%[0-9A-Z]{0,2})") {
set $block_common_exploits 1;
}
if ($query_string ~ "_REQUEST(=|\[|\%[0-9A-Z]{0,2})") {
set $block_common_exploits 1;
}
if ($query_string ~ "proc/self/environ") {
set $block_common_exploits 1;
}
if ($query_string ~ "mosConfig_[a-zA-Z_]{1,21}(=|\%3D)") {
set $block_common_exploits 1;
}
if ($query_string ~ "base64_(en|de)code\(.*\)") {
set $block_common_exploits 1;
}
if ($block_common_exploits = 1) {
return 500;
}

## Block spam
set $block_spam 0;
if ($query_string ~ "\b(ultram|unicauca|valium|viagra|vicodin|xanax|ypxaieo)\b") {
set $block_spam 1;
}
if ($query_string ~ "\b(erections|hoodia|huronriveracres|impotence|levitra|libido)\b") {
set $block_spam 1;
}
if ($query_string ~ "\b(ambien|blue\spill|cialis|cocaine|ejaculation|erectile)\b") {
set $block_spam 1;
}
if ($query_string ~ "\b(lipitor|phentermin|pro[sz]ac|sandyauer|tramadol|troyhamby)\b") {
set $block_spam 1;
}
if ($block_spam = 1) {
return 500;
}

## Block user agents
set $block_user_agents 0;

# Don't disable wget if you need it to run cron jobs!
#if ($http_user_agent ~ "Wget") {
# set $block_user_agents 1;
#}

# Disable Akeeba Remote Control 2.5 and earlier
if ($http_user_agent ~ "Indy Library") {
set $block_user_agents 1;
}

# Common bandwidth hoggers and hacking tools.
if ($http_user_agent ~ "libwww-perl") {
set $block_user_agents 1;
}
if ($http_user_agent ~ "GetRight") {
set $block_user_agents 1;
}
if ($http_user_agent ~ "GetWeb!") {
set $block_user_agents 1;
}
if ($http_user_agent ~ "Go!Zilla") {
set $block_user_agents 1;
}
if ($http_user_agent ~ "Download Demon") {
set $block_user_agents 1;
}
if ($http_user_agent ~ "Go-Ahead-Got-It") {
set $block_user_agents 1;
}
if ($http_user_agent ~ "TurnitinBot") {
set $block_user_agents 1;
}
if ($http_user_agent ~ "GrabNet") {
set $block_user_agents 1;
}

if ($block_user_agents = 1) {
return 500;
}

#some bot does not send user-agent, just block them
if ($http_user_agent = "") {
set $proxyflag "forbidden";
return 500;
}
#security for timthumb remote code execution exploit
if ($request_uri ~* "\.php.*src=.*(flickr\.com|picasa\.com|blogger\.com|wordpress\.com|img\.youtube\.com|upload\.wikimedia\.org|photobucket\.com|imgur\.com|imageshack\.us|tinypic\.com)") {
set $proxyflag "forbidden";
return 500;
}

#cached and upload folder should not have any php file
if ($request_uri ~* "/cache/.*\.php") {
set $proxyflag "forbidden";
return 500;
}
if ($request_uri ~* "/uploads?/.*\.php") {
set $proxyflag "forbidden";
return 500;
}

if ($request_uri ~* "/images?/.*\.php") {
set $proxyflag "forbidden";
return 500;
}

#bad behavior url (known botnet/trojan)
if ($request_uri ~* "\?.*eval\(") {
set $proxyflag "forbidden";
return 500;
}
if ($request_body ~* "\?.*eval\(") {
set $proxyflag "forbidden";
return 500;
}
if ($request_body ~* "