alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET RETIRED Win32/S1deload Stealer CnC Checkin"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/commonupdate?version="; startswith; fast_pattern; pcre:"/^(?:[A-F0-9]{4}-){7}[A-F0-9]{4}/R"; content:"&uuid="; distance:0; pcre:"/^[a-f0-9]{8}-(?:[a-f0-9]{4}-){3}[a-f0-9]{12}/R"; http.header_names; content:"|0d 0a|Host|0d 0a|Connection|0d 0a 0d 0a|"; bsize:22; reference:url,www.bitdefender.com/files/News/CaseStudies/study/428/Bitdefender-PR-Whitepaper-S1deloadStealer-creat6669-en-EN.pdf; classtype:trojan-activity; sid:2044359; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2023_02_27, deployment Perimeter, former_category MALWARE, malware_family Win32_S1deload, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_09_30, reviewed_at 2024_09_30;)