uknown hacking atemps

I can see a lot strange activities in my website (CentOS6.0-64 Minimal for VS) Apache log like this one

if i try to navigate to it this is what I see below.
can anyone tell me what are they after?

d7aa4ad6f7a7fbadb117f6ef8a20d184||force-no-vary=>|downgrade-1_0=>|HTTP_HOST=>|HTTP_X_REAL_IP=>|HTTP_CONNECTION=>close|HTTP_USER_AGENT=>Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:37.0) Gecko/20100101 Firefox/37.0|HTTP_ACCEPT=>text/html,application/xhtml+xml,application/xml;q0.9,*/*;q0.8|HTTP_ACCEPT_LANGUAGE=>en-US,en;q0.5|HTTP_ACCEPT_ENCODING=>gzip, deflate|PATH=>/usr/local/bin:/usr/bin:/bin|SERVER_SIGNATURE=>|SERVER_SOFTWARE=>Apache|SERVER_NAME=>|SERVER_PORT=>80|REMOTE_ADDR=>|DOCUMENT_ROOT=>/|SERVER_ADMIN=>[no address given]|SCRIPT_FILENAME=>/|REMOTE_PORT=>37295|GATEWAY_INTERFACE=>|SERVER_PROTOCOL=>HTTP/1.0|REQUEST_METHOD=>GET|QUERY_STRING=>|REQUEST_URI=>/|SCRIPT_NAME=>/|REQUEST_TIME=>1431686922|DOCUMENT_URI=>/|USER=>|HOME=>||||||
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Zephyr ICTCloud ArchitectCommented:
Likely it's a already compromised host doing some kind of port/vulnerability scanning on your host... What response does your webserver give on these requests? If it's 404 then you're probably ok...

I'd block this host in iptables to be on the safe side though.
somebody dumped your cgi environment using shellshock vulnerability. you must update sometimes
leop1212Author Commented:
what do I have to update ? what other action do you recomend
Your server might have been hacked (or as minimum somebody gained access to apache user)
You must upgrade system (yum upgrade -y bash at least to close vulnerebility exploited in your post, or much better yum upgrade -y)

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