alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/LockScreen CnC Beacon 2"; flow:established,to_server; urilen:8; http.method; content:"GET"; http.uri; content:"/cou.php"; fast_pattern; http.header; content:"Host|3a|"; depth:5; pcre:"/^Host\x3a[^\r\n]+\r\n(?:\r\n)?$/"; http.header_names; content:!"User-Agent|0d 0a|"; content:!"Accept"; content:!"Referer|0d 0a|"; reference:md5,046e4b3ff7b323f2147f2d5d43b7e5f4; reference:md5,e4ab12da8828a7f1e6c077a2999f8320; classtype:command-and-control; sid:2020504; rev:4; metadata:attack_target Client_Endpoint, created_at 2015_02_24, deployment Perimeter, malware_family Win32_LockScreen, signature_severity Major, tag c2, updated_at 2020_09_29, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)