alert http $EXTERNAL_NET any -> $HOME_NET any (
msg:"ET HUNTING SUSPICIOUS PSHELL Downloader Primitives B645W Oct 19 2017";
flow:established,from_server;
file_data;
content:"TAHQAYQByAHQALQBQAHIAbwBjAGUAcwBz";
pcre:"/(?:RABvAHcAbgBsAG8AYQBkAEYAaQBsAG|QAbwB3AG4AbABvAGEAZABGAGkAbABl|EAG8AdwBuAGwAbwBhAGQARgBpAGwAZ)/";
pcre:"/(?:VwByAGkAdABlAC0ASABvAHMAd|cAcgBpAHQAZQAtAEgAbwBzAH|XAHIAaQB0AGUALQBIAG8AcwB0)/";
pcre:"/(?:UwB5AHMAdABlAG0ALgBOAGUAdAAuAFcAZQBiAEMAbABpAGUAbgB0|MAeQBzAHQAZQBtAC4ATgBlAHQALgBXAGUAYgBDAGwAaQBlAG4Ad|TAHkAcwB0AGUAbQAuAE4AZQB0AC4AVwBlAGIAQwBsAGkAZQBuAH)/";
classtype:trojan-activity;
sid:2024883; rev:2;
metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_10_20, deployment Perimeter, malware_family Locky, performance_impact Low, confidence Medium, signature_severity Major, updated_at 2019_07_26;
)