alert tcp $HOME_NET any -> $EXTERNAL_NET 1024: (msg:"ET MALWARE DDoS Win32/Nitol.A Checkin"; flow:established,to_server; dsize:1000<>1300; content:"|fe ff ff ff|"; content:"|00 00|Win|20|"; fast_pattern; content:"|20|MB"; byte_test:1,>,0x29,-7,relative; byte_test:1,<,0x40,-7,relative; content:"MHz"; distance:0; byte_test:1,>,0x29,-7,relative; byte_test:1,<,0x40,-7,relative; content:"bps"; distance:0; content:"|20|"; distance:-5; within:1; byte_test:1,>,0x29,-2,relative; byte_test:1,<,0x40,-2,relative; reference:md5,990955327075071d4aa1f73c3c6c7e7f; reference:url,blog.netlab.360.com/public-cloud-threat-intelligence-202203/; classtype:command-and-control; sid:2036414; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2018_02_01, deployment Perimeter, malware_family Nitol_DDoS, performance_impact Low, confidence Medium, signature_severity Major, updated_at 2019_07_26;)