alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET EXPLOIT Linux/Attempted Hosts File Exfil"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"?url=file|3a 2f 2f 2f|etc|2f|hosts"; endswith; http.header_names; content:!"Referer"; classtype:attempted-admin; sid:2035315; rev:2; metadata:affected_product Linux, attack_target Server, created_at 2022_02_28, deployment Perimeter, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_02_28, reviewed_at 2024_06_26;)