alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Small.NO Checkin"; flow:established,to_server; stream_size:server,<,5; dsize:76; content:"MB|00 00|"; offset:32; depth:9; content:"|32 2e 32 d5 fd ca bd b0 e6 00 00 00|"; endswith; fast_pattern; reference:md5,e09e70ae301e0816355ad0bfa0ab8707; classtype:command-and-control; sid:2034301; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2021_10_29, deployment Perimeter, malware_family Win32_Small_NO, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_10_29;)