alert http $HOME_NET any -> $EXTERNAL_NET [$HTTP_PORTS,886] (msg:"ET MALWARE Win32/PSW.Agent.OIN CnC Activity"; flow:established,to_server; http.start; content:"POST / HTTP/1.1|0d 0a|Connection|3a 20|Keep-Alive|0d 0a|Accept|3a 20|*/*|0d 0a|Accept-Language|3a 20|en-US,en|3b|q=0.9|0d 0a|User-Agent|3a 20|Mozilla/5.0 (Windows NT 10.0|3b 20|Win64|3b 20|x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36|0d 0a|Content-Length|3a 20|"; startswith; fast_pattern; http.header_names; content:!"|0d 0a|Referer|0d 0a|"; http.request_body; content:!"&"; pcre:"/^(?:[a-zA-Z0-9+/\x20]{4})*(?:[a-zA-Z0-9+/\x20]{2}==|[a-zA-Z0-9+/\x20]{3}=|[a-zA-Z0-9+/\x20]{4})$/"; reference:md5,4589aaf8f84c91c5e290ddebcc368342; classtype:command-and-control; sid:2030560; rev:1; metadata:attack_target Client_Endpoint, created_at 2020_07_20, deployment Perimeter, malware_family Win32_PSW_Agent_OIN, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_07_20;)