alert tcp $EXTERNAL_NET $HTTP_PORTS -> $HOME_NET any (msg:"ET EXPLOIT_KIT Document.write Long Backslash UTF-16 Encoded Content - Exploit Kit Behavior Flowbit Set"; flow:established,to_client; content:"document.write|28 22 5C|u"; nocase; isdataat:100,relative; content:!"|29|"; within:100; content:"|5C|u"; nocase; distance:4; within:2; content:"|5C|u"; nocase; distance:4; within:2; content:"|5C|u"; nocase; distance:4; within:2; content:"|5C|u"; nocase; distance:70; content:"|5C|u"; nocase; distance:4; within:2; flowbits:set,et.exploitkitlanding; flowbits:noalert; reference:url,www.kahusecurity.com/2011/elaborate-black-hole-infection/; classtype:exploit-kit; sid:2014096; rev:6; metadata:created_at 2012_01_04, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)