alert tcp-pkt $HOME_NET any -> $EXTERNAL_NET 443 (msg:"ET MALWARE Win32/Bumblebee Loader Checkin Activity (set)"; flow:established,to_server; flowbits:set,et.bumblebee; flowbits:noalert; dsize:4; content:"|00 00 00|"; endswith; fast_pattern; reference:md5,270103c51888a8e98972283c825d84cd; classtype:trojan-activity; sid:2047945; rev:1; metadata:attack_target Client_Endpoint, created_at 2023_09_07, deployment Perimeter, malware_family Win32_Bumblebee, performance_impact Moderate, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_09_07, reviewed_at 2024_04_08; target:src_ip;)