alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Ymacco.AA1C Activity"; flow:established,to_server; http.method; content:"GET"; http.uri; content:".php?REQ="; fast_pattern; content:"&ID="; distance:0; http.user_agent; content:"|29 20|WindowsPowerShell/"; http.header_names; content:!"Accept"; content:!"Referer"; reference:md5,b100f0ab63a2b74a5d5ff54d533fc60f; classtype:trojan-activity; sid:2031477; rev:1; metadata:attack_target Client_Endpoint, created_at 2021_01_04, deployment Perimeter, malware_family Win32_Ymacco_AA1C, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_01_04;)