Netcat File Transfer or Listener Detected via Defend for Containers

process where host.os.type == "linux" and event.type == "start" and event.action == "exec" and (
  process.name in ("nc","ncat","netcat","netcat.openbsd","netcat.traditional") or
  (
    /* account for tools that execute utilities as a subprocess, in this case the target utility name will appear as a process arg */
    process.name in ("bash", "dash", "sh", "tcsh", "csh", "zsh", "ksh", "fish", "busybox") and
    process.args in (
      "nc", "/bin/nc", "/usr/bin/nc", "/usr/local/bin/nc",
      "ncat", "/bin/ncat", "/usr/bin/ncat", "/usr/local/bin/ncat",
      "netcat", "/bin/netcat", "/usr/bin/netcat", "/usr/local/bin/netcat",
      "netcat.openbsd", "/bin/netcat.openbsd", "/usr/bin/netcat.openbsd", "/usr/local/bin/netcat.openbsd",
      "netcat.traditional", "/bin/netcat.traditional", "/usr/bin/netcat.traditional", "/usr/local/bin/netcat.traditional"
    ) and 
    /* default exclusion list to not FP on default multi-process commands */
    not process.args in (
      "which", "/bin/which", "/usr/bin/which", "/usr/local/bin/which",
      "man", "/bin/man", "/usr/bin/man", "/usr/local/bin/man",
      "chmod", "/bin/chmod", "/usr/bin/chmod", "/usr/local/bin/chmod",
      "chown", "/bin/chown", "/usr/bin/chown", "/usr/local/bin/chown"
    )
  )
) and
process.args like~ (
  /* bind shell to specific port or listener */
  "-*l*","-*p*",
  /* reverse shell to command-line interpreter used for command execution */
  "-*e*",
  /* file transfer via stdout/pipe */
  ">","<", "
| "
) and container.id like "*"

False Positives

• ⚠ There is a potential for false positives if the container is used for legitimate tasks that require the use of netcat, such as network troubleshooting, testing or system monitoring. It is important to investigate any alerts generated by this rule to determine if they are indicative of malicious activity or part of legitimate container activity.