Command and Control (TA0011)(opens in a new tab or window)
sequence by host.id, process.entity_id with maxspan=1s
[process where host.os.type == "linux" and event.type == "start" and event.action == "exec" and
process.name == "cat" and process.parent.name in ("bash", "dash", "sh", "tcsh", "csh", "zsh", "ksh", "fish")]
[network where host.os.type == "linux" and event.action in ("connection_attempted", "disconnect_received") and
process.name == "cat" and not (destination.ip == null or destination.ip == "0.0.0.0" or cidrmatch(
destination.ip, "10.0.0.0/8", "127.0.0.0/8", "169.254.0.0/16", "172.16.0.0/12", "192.0.0.0/24", "192.0.0.0/29",
"192.0.0.8/32", "192.0.0.9/32", "192.0.0.10/32", "192.0.0.170/32", "192.0.0.171/32", "192.0.2.0/24",
"192.31.196.0/24", "192.52.193.0/24", "192.168.0.0/16", "192.88.99.0/24", "224.0.0.0/4", "100.64.0.0/10",
"192.175.48.0/24","198.18.0.0/15", "198.51.100.0/24", "203.0.113.0/24", "240.0.0.0/4", "::1", "FE80::/10",
"FF00::/8"
)
)]
Install detection rules in Elastic Security
Detect Network Activity Detected via cat 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(opens in a new tab or window).