alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE TrueBot/Silence.Downloader CnC Checkin 3"; flow:established,to_server; http.method; content:"POST"; http.uri; content:".php"; endswith; http.request_body; content:"q="; depth:2; pcre:"/^q=(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})$/i"; http.request_line; content:".php HTTP/1.0"; endswith; fast_pattern; http.header_names; content:!"Referer"; content:!"Accept"; content:!"User-Agent"; reference:md5,f1a4e74e72390ef98c23f19589d3c7cd; reference:url,blog.talosintelligence.com/breaking-the-silence-recent-truebot-activity/; classtype:command-and-control; sid:2042959; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2019_01_17, deployment Perimeter, confidence High, signature_severity Major, tag Truebot, updated_at 2022_12_19, former_sid 2834446;)