alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/1xxbot CnC Checkin"; flow:established,to_server; dsize:<250; content:"|00|<EOM>Windows|20|"; startswith; fast_pattern; content:"<EOM>"; distance:0; content:"<EOM>"; distance:0; content:"<EOM>"; distance:0; content:"<EOF>"; endswith; reference:md5,9eb50c6cdb59d11b01ca9f069e8ba79d; classtype:command-and-control; sid:2028984; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2019_11_15, deployment Perimeter, deprecation_reason Age, malware_family 1xxbot, confidence High, signature_severity Major, updated_at 2023_12_21, reviewed_at 2023_12_21;)