alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Kimsuky Related CnC Activity"; flow:established,to_server; http.method; content:"GET"; http.uri; pcre:"/https:\/\/[a-z0-9]{8}-[a-z0-9]{4}-[a-z0-9]{4}-[a-z0-9]{4}-[a-z0-9]{12}.[a-z]{3,12}.com\/[a-z]{3,4}\/[a-z0-9]{6}_[a-z0-9]{32}/"; content:".xls?dn="; fast_pattern; content:".xls"; endswith; reference:url,github.com/eset/malware-ioc/tree/master/kimsuky/hotdoge_donutcat_case; classtype:trojan-activity; sid:2034696; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2021_12_13, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_12_13;)