alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MOBILE_MALWARE Trojan-Spy.AndroidOS.Femas.b CnC Beacon"; flow:established,to_server; http.method; content:"POST"; nocase; http.uri; content:".php"; endswith; http.content_type; bsize:33; content:"application/x-www-form-urlencoded"; http.header; header_lowercase; content:"content-language|3a 20|en-US|0d 0a|"; http.connection; bsize:10; content:"Keep-Alive"; http.user_agent; content:"|3b 20|Android|20|"; http.request_body; content:"&method="; fast_pattern; pcre:"/^d(?:id|ei)=[A-F0-9]{10,100}&method=IS[A-Z]{1,10}$/"; http.header_names; to_lowercase; content:!"|0d 0a|referer|0d 0a|"; content:"|0d 0a|content-type|0d 0a|content-language|0d 0a|connection|0d 0a|"; reference:md5,d6ef9b0cdb49b56c53da3433e30f3fd6; reference:md5,4ddf3ff57db24513a16eacb99ad07675; reference:url,securelist.com/blog/incidents/77562/breaking-the-weakest-link-of-the-strongest-chain/; classtype:command-and-control; sid:2023933; rev:8; metadata:affected_product Android, attack_target Client_Endpoint, created_at 2017_02_16, deployment Perimeter, confidence High, signature_severity Major, tag Android, tag c2, updated_at 2024_05_04, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)