alert tcp $EXTERNAL_NET $HTTP_PORTS -> $HOME_NET any (msg:"ET WEB_CLIENT Possible Internet Explorer CSS Parser Remote Code Execution Attempt"; flow:established,to_client; content:"@import url(|22|"; nocase; content:"css|22|)|3B|"; nocase; within:40; content:"@import url(|22|"; nocase; distance:0; content:"css|22|)|3B|"; nocase; within:40; content:"@import url(|22|"; nocase; distance:0; content:"css|22|)|3B|"; nocase; within:40; content:"@import url(|22|"; nocase; distance:0; content:"css|22|)|3B|"; nocase; within:40; reference:url,seclists.org/fulldisclosure/2010/Dec/110; reference:url,www.breakingpointsystems.com/community/blog/ie-vulnerability/; reference:url,seclists.org/fulldisclosure/2010/Dec/110; reference:url,www.breakingpointsystems.com/community/blog/ie-vulnerability/; reference:url,www.microsoft.com/technet/security/advisory/2488013.mspx; reference:bid,45246; reference:cve,2010-3971; classtype:attempted-user; sid:2012075; rev:2; metadata:affected_product Web_Browsers, affected_product Web_Browser_Plugins, attack_target Client_Endpoint, created_at 2010_12_18, deployment Perimeter, confidence Medium, signature_severity Major, tag Web_Client_Attacks, updated_at 2019_07_26, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application;)