alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE ChaChi RAT Client CnC (POST)"; flow:established,to_server; flowbits:set,ET.chachirat; http.method; content:"POST"; http.uri; bsize:10; content:"/time/sync"; fast_pattern; http.user_agent; content:"Go-http-client/"; startswith; http.host; pcre:"/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/"; http.header_names; to_lowercase; content:!"|0d 0a|referer|0d 0a|"; reference:url,blogs.blackberry.com/en/2021/06/pysa-loves-chachi-a-new-golang-rat; reference:md5,9976373177d217207a692a6d0867e9c4; classtype:trojan-activity; sid:2033184; rev:4; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2021_06_24, deployment Perimeter, confidence High, signature_severity Major, tag RAT, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_30;)