alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Tortoiseshell/SysKit CnC Activity"; flow:established,to_server; http.method; content:"POST"; http.uri; content:!"&"; content:!"."; http.request_body; content:"ip="; depth:3; content:"#"; distance:0; content:"&os="; distance:0; content:"#"; distance:0; content:"&os_name="; distance:0; fast_pattern; content:"#"; distance:0; content:"&mac="; distance:0; http.header_names; content:!"Referer"; content:!"User-Agent"; reference:md5,a194e3bf830104922295c37e6d19d9a2; reference:url,blog.talosintelligence.com/2019/09/tortoiseshell-fake-veterans.html; reference:url,symantec-enterprise-blogs.security.com/blogs/threat-intelligence/tortoiseshell-apt-supply-chain; classtype:command-and-control; sid:2028618; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2019_09_24, deployment Perimeter, performance_impact Moderate, confidence High, signature_severity Major, updated_at 2020_09_02;)