alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"GPL WEB_CLIENT PNG large colour depth download attempt"; flow:from_server,established; content:"|89|PNG|0D 0A 1A 0A|"; content:"IHDR"; within:8; byte_test:1,>,16,8,relative; reference:bugtraq,11523; reference:cve,2004-0990; reference:cve,2004-1244; reference:url,www.microsoft.com/technet/security/bulletin/MS05-009.mspx; classtype:attempted-user; sid:2103134; rev:5; metadata:affected_product Web_Browsers, affected_product Web_Browser_Plugins, attack_target Client_Endpoint, created_at 2010_09_23, deployment Perimeter, confidence Medium, signature_severity Major, tag Web_Client_Attacks, updated_at 2019_07_26;)