alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"GPL WEB_CLIENT web bug 0x0 gif attempt"; flow:from_server,established; content:"Content-type|3A| image/gif"; nocase; content:"GIF"; distance:0; nocase; content:"|01 00 01 00|"; within:4; distance:3; content:","; distance:0; content:"|01 00 01 00|"; within:4; distance:4; classtype:misc-activity; sid:2102925; 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;)