alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Trickbot Payload Request"; flow:to_server,established; http.method; content:"GET"; http.uri; pcre:"/^\/(?:kas|ser|mac)[0-9]+\.png$/i"; http.start; content:".png HTTP/1.1|0d 0a|Host|3a 20|"; fast_pattern; http.header_names; content:!"Accept"; content:!"Referer|0d 0a|"; content:!"User-Agent|0d 0a|"; reference:md5,2c6cd25a31fe097ee7532422fc8eedc8; classtype:trojan-activity; sid:2024901; rev:7; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_10_23, deployment Perimeter, performance_impact Significant, confidence High, signature_severity Major, tag Trickbot, updated_at 2024_04_08;)