alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE RATatouille rand-user-agent Supply Chain Compromise CnC Activity (POST)"; flow:established,to_server; flowbits:set,ET.RATatouille.Connect; urilen:4; http.method; content:"POST"; http.uri; content:"/u/f"; fast_pattern; http.user_agent; content:"python-requests"; nocase; http.request_body; content:"form|2d|data|3b 20|name|3d 22|client|5f|id|22|"; content:"|24|"; distance:0; content:"Content|2d|Disposition|3a 20|form|2d|data|3b 20|name|3d 22|path|22|"; distance:0; reference:md5,c1b54de2dde3c72eab2b7b2e9ae76ea4; reference:url,aikido.dev/blog/catching-a-rat-remote-access-trojian-rand-user-agent-supply-chain-compromise; classtype:command-and-control; sid:2062283; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Linux, attack_target Client_Endpoint, tls_state plaintext, created_at 2025_05_12, deployment Perimeter, signature_severity Critical, updated_at 2025_05_12, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol; target:src_ip;)