alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE IIS Backdoor CnC Command Inbound"; flow:established,to_server; http.method; content:"GET"; http.uri; content:".aspx"; endswith; http.cookie; content:"EX_TOKEN|3d|"; fast_pattern; startswith; http.header_names; content:!"Referer"; reference:url,www.microsoft.com/security/blog/2022/07/26/malicious-iis-extensions-quietly-open-persistent-backdoors-into-servers/; classtype:trojan-activity; sid:2037845; rev:1; metadata:affected_product Microsoft_IIS, attack_target Web_Server, created_at 2022_07_28, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_07_28, reviewed_at 2024_09_17;)