ET EXPLOIT_KIT Document.write Long Backslash UTF-16 Encoded Content - Exploit Kit Behavior Flowbit Set

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;
)