alert tcp $EXTERNAL_NET any -> $HOME_NET any (msg:"ET SCAN NMAP -sS window 2048"; fragbits:!D; dsize:0; flags:S,12; ack:0; window:2048; threshold:type both, track by_dst, count 1, seconds 60; classtype:attempted-recon; sid:2000537; rev:8; metadata:created_at 2010_07_30, confidence Low, signature_severity Informational, updated_at 2019_07_26;)