alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Py/MechaFlounder CnC Checkin"; flow:established,to_server; http.method; content:"GET"; http.uri; content:!"|2f|"; depth:1; content:"--"; content:"|5c|"; content:"-service.html"; fast_pattern; endswith; http.header_names; content:!"Referer"; content:!"User-Agent"; reference:url,unit42.paloaltonetworks.com/new-python-based-payload-mechaflounder-used-by-chafer/; classtype:command-and-control; sid:2027047; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Python, attack_target Client_and_Server, created_at 2019_03_06, deployment Perimeter, malware_family MechaFlounder, performance_impact Low, confidence High, signature_severity Major, tag APT, tag Chafer, tag Python, updated_at 2020_09_16;)