alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE JS/WSF Downloader Dec 08 2016"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/counter/?"; fast_pattern; startswith; content:"&r="; pcre:"/^\/counter\/\?(?:[a-z]=(?:0\.\d{8}|1[A-Z0-9a-z]+))+&r=\d+$/"; http.user_agent; content:"Mozilla/4.0 (compatible|3b| MSIE 7.0|3b|"; startswith; http.header_names; content:!"|0d 0a|Referer|0d 0a|"; content:!"|0d 0a|Cookie|0d 0a|"; classtype:trojan-activity; sid:2023594; rev:6; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2016_12_09, deployment Perimeter, malware_family Trojan_Kwampirs, performance_impact Low, signature_severity Major, updated_at 2024_03_04;)