alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET WEB_CLIENT Malicious SCF File Inbound"; flow:to_client,established; file_data; content:"[shell]"; nocase; content:"iconfile"; nocase; distance:0; pcre:"/^\s*=\s*\x5c\x5c/Rs"; reference:url,defensecode.com/news_article.php?id=21; classtype:attempted-user; sid:2024303; rev:3; metadata:affected_product Windows_Client_Apps, attack_target Client_Endpoint, created_at 2017_05_16, deployment Perimeter, performance_impact Moderate, signature_severity Minor, updated_at 2020_08_19;)