alert tcp-pkt $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/XRat.AT Variant CnC Activity"; flow:established,to_server; content:"0|7c|SS Client ID|7c|"; startswith; fast_pattern; content:"Windows"; distance:0; reference:md5,35b93cc523e0ac8c9bb922a236416d6f; classtype:command-and-control; sid:2032888; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2021_04_29, deployment Perimeter, malware_family Win32_XRat_AT, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_04_29;)