Defense Evasion (TA0005)(external, opens in a new tab or window)
text code block:process where host.os.type == "linux" and event.type == "start" and event.action == "exec" and process.interactive == true and ( (process.name in ("base64", "base64plain", "base64url", "base64mime", "base64pem", "base32", "base16") and process.args like~ "*-*d*") or (process.name == "xxd" and process.args like~ ("-*r*", "-*p*")) or (process.name == "openssl" and process.args == "enc" and process.args in ("-d", "-base64", "-a")) or (process.name like "python*" and ( (process.args == "base64" and process.args in ("-d", "-u", "-t")) or (process.args == "-c" and process.args like "*base64*" and process.args like "*b64decode*") )) or (process.name like "perl*" and process.args like "*decode_base64*") or (process.name like "ruby*" and process.args == "-e" and process.args like "*Base64.decode64*") ) and container.id like "?*"
Install detection rules in Elastic Security
Detect Encoded Payload Detected via Defend for Containers in the Elastic Security detection engine by installing this rule into your Elastic Stack.
To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(external, opens in a new tab or window).