POP3: Request Error Unknown Command
This protocol anomaly triggers when it detects an unknown POP3 command during the command portion of a POP3 connection. This can indicate an experimental version of POP3 or a back-door/exploit attempt.
References
srx-branch-12.3
srx-19.3
srx-branch-19.3
vsrx3bsd-19.2
srx-branch-19.4
vsrx-19.4
mx-12.3
mx-19.4
vmx-19.4
mx-19.3
vsrx3bsd-19.4
srx-19.4
vsrx-12.3
vmx-19.3
vsrx-19.2
srx-12.3