alert dns $HOME_NET any -> any any (msg:"ET MALWARE Anchor_DNS Trickbot DNS CnC Command - Receive Data"; content:"|00 00 00 00 00 00 32 38 42|"; fast_pattern; dns.query; content:"8B"; startswith; nocase; content:"B9."; nocase; distance:46; within:3; pcre:"/^8b[a-fA-F0-9]{46}b9\./i"; reference:url,technical.nttsecurity.com/post/102fsp2/trickbot-variant-anchor-dns-communicating-over-dns; classtype:command-and-control; sid:2028882; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2019_10_21, deployment Perimeter, malware_family TrickBot, confidence Medium, signature_severity Major, tag Trickbot, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_12;)