alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET WEB_CLIENT Microsoft OLE Compound File Magic Bytes Flowbit Set"; flow:to_client,established; file_data; content:"|d0 cf 11 e0 a1 b1 1a e1|"; within:8; content:!".msi"; flowbits:set,OLE.CompoundFile; flowbits:noalert; classtype:protocol-command-decode; sid:2012520; rev:7; metadata:affected_product Web_Browsers, affected_product Web_Browser_Plugins, attack_target Client_Endpoint, created_at 2010_12_15, deployment Perimeter, confidence Medium, signature_severity Major, tag Web_Client_Attacks, updated_at 2019_07_26;)