#alert tcp $EXTERNAL_NET $HTTP_PORTS -> $HOME_NET any (msg:"ET POLICY Nginx Server in use - Often Hostile Traffic"; flow:established,from_server; content:"HTTP/1."; depth:7; content:"|0d 0a|Server\: nginx"; nocase; distance:4; within:300; threshold:type limit, seconds 60, count 3, track by_src; classtype:bad-unknown; sid:2008054; rev:2;)

Added 2008-03-28 13:33:34 UTC

Disabled by default. Nginx was too widespread to be called more often than not hostile. 2008064 and 2008065 are better fits for modified version strings of nginx.

-- MattJonkman - 28 Mar 2008

#alert tcp $EXTERNAL_NET $HTTP_PORTS -> $HOME_NET any (msg:"ET POLICY Nginx Server in use - Often Hostile Traffic"; flow:established,from_server; content:"HTTP/1."; depth:7; content:"|0d 0a|Server\: nginx"; nocase; distance:4; within:300; threshold:type limit, seconds 60, count 3, track by_src; classtype:bad-unknown; sid:2008054; rev:2;)

Added 2008-03-28 13:33:34 UTC

alert tcp $EXTERNAL_NET $HTTP_PORTS -> $HOME_NET any (msg:"ET POLICY Nginx Server in use - Often Hostile Traffic"; flow:established,from_server; content:"HTTP/1."; depth:7; content:"|0d 0a|Server\: nginx"; nocase; distance:4; within:30; threshold:type limit, seconds 60, count 3, track by_src; classtype:bad-unknown; sid:2008054; rev:1;)

Added 2008-03-26 15:01:39 UTC

http://nginx.net/

It's a legit piece of software, but it's very often used in malicious sites.

-- MattJonkman - 26 Mar 2008