alert tcp $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Arechclient2 Backdoor CnC Keep-Alive"; flow:established,from_server; dsize:<100; content:"|7b 22 54 79 70 65 22 3a 22 53 65 73 73 69 6f 6e 49 44 22 2c 22 53 65 73 73 69 6f 6e 49 44 22 3a 22|"; fast_pattern; depth:50; content:"|7d|"; endswith; reference:md5,4ccba79d95dfd7d87b43643058e1cdd0; classtype:command-and-control; sid:2029219; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_01_02, deployment Perimeter, malware_family Arechclient2, confidence High, signature_severity Major, updated_at 2022_03_24, reviewed_at 2024_05_06;)