alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET RETIRED Truebot/Silence.Downloader No Tasking Response from Server"; flow:established,to_client; http.stat_code; content:"200"; file.data; content:"404NOTFOUND"; fast_pattern; startswith; reference:md5,f1a4e74e72390ef98c23f19589d3c7cd; reference:url,blog.talosintelligence.com/breaking-the-silence-recent-truebot-activity/; classtype:command-and-control; sid:2045298; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2023_05_02, deployment Perimeter, deployment SSLDecrypt, former_category MALWARE, malware_family TrueBot, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_04_17, reviewed_at 2025_04_17; target:dest_ip;)