alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/TrickBot maserv Module CnC Activity"; flow:to_server,established; http.method; content:"POST"; http.uri; content:"/81"; endswith; http.request_body; content:"Content-Disposition|3a 20|form-data|3b 20|name=|22|data|22 0d 0a 0d 0a|"; content:"|0d 0a|Content-Disposition|3a 20|form-data|3b 20|name=|22|source|22 0d 0a 0d 0a|PORT|20|scan|0d 0a|"; nocase; distance:0; fast_pattern; http.header_names; content:!"Referer"; reference:url,www.kryptoslogic.com/blog/2021/02/trickbot-masrv-module/; reference:md5,ff57c02b09cd9df4d1cac5090e01a5d2; classtype:trojan-activity; sid:2031601; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2021_02_02, deployment Perimeter, malware_family TrickBot, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_02_02;)