alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Sinresby.B Downloader CnC Activity M1"; flow:established,to_server; http.request_line; content:"POST /?c=Public&a=get_config"; startswith; fast_pattern; http.user_agent; content:"Mozilla|2f|4|2e|0|20 28|compatible|3b 20|MSIE|20|9|2e|0|3b 20|Windows|20|NT|20|6|2e|1|29|"; bsize:50; http.referer; content:"/?c=Public&a=get_config"; endswith; reference:md5,8049009d9675d5ac345ce96d1a7c9e67; classtype:command-and-control; sid:2033792; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2021_08_25, deployment Perimeter, malware_family Win32_Sinresby_B, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_08_25;)