alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET HUNTING Microsoft Office User-Agent Requesting An Excel File"; flow:established,to_server; http.method; content:"GET"; http.uri; pcre:"/\x2exls[xm]?$/"; http.user_agent; content:"|3b 20|ms|2d|office|3b|"; fast_pattern; classtype:bad-unknown; sid:2037156; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2022_06_29, deployment Perimeter, performance_impact Moderate, confidence Medium, signature_severity Minor, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_06_29;)