alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Possible AMSI Powershell Bypass Attempt"; flow:established,from_server; file_data; content:"<script"; nocase; content:"powershell"; nocase; distance:0; content:"System.Management.Automation.AmsiUtils"; fast_pattern; nocase; content:"amsiInitFailed"; nocase; content:"setvalue"; nocase; content:"$null"; nocase; distance:0; content:"$true"; nocase; distance:0; classtype:trojan-activity; sid:2024537; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_08_11, deployment Perimeter, confidence Medium, signature_severity Major, updated_at 2019_07_26;)