alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET USER_AGENTS Suspcious LeakIX User-Agent (l9explore)"; flow:established,to_server; http.user_agent; content:"l9explore"; startswith; fast_pattern; reference:url,ithub.com/LeakIX/l9format; classtype:bad-unknown; sid:2035314; rev:2; metadata:affected_product Linux, attack_target Server, created_at 2022_02_28, deployment Perimeter, confidence High, signature_severity Minor, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_02_28;)