alert tcp $HOME_NET any -> $EXTERNAL_NET 1024: (msg:"ET MALWARE Win32/Delf.OKR Variant CnC M1"; flow:established,to_server; stream_size:server,<,5; content:"|3d 22 3f 4b 0a|"; startswith; reference:md5,320564554767ddd328932997067f64a5; classtype:command-and-control; sid:2033949; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2021_09_14, deployment Perimeter, malware_family Win32_Delf_OKR, performance_impact Moderate, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_09_14;)