alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Ursnif Variant CnC Beacon - URI Struct M2 (_2F)"; flow:established,to_server; http.method; content:"GET"; http.uri; bsize:>150; content:"_2F"; fast_pattern; content:"_2F"; distance:0; content:"_2F"; distance:0; content:!"&"; content:!"?"; content:!"="; content:!"/tr/v1/"; startswith; http.host; dotprefix; content:!".surveymonkey.com"; endswith; content:!"cisco.com"; endswith; http.connection; content:"Keep-Alive"; http.header_names; content:!"|0d 0a|Referer|0d 0a|"; classtype:command-and-control; sid:2033204; rev:4; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2021_06_29, deployment Perimeter, malware_family ursnif, performance_impact Moderate, confidence High, signature_severity Major, updated_at 2023_06_12;)