Adversaries may leverage traffic mirroring in order to automate data exfiltration over compromised network infrastructure. Traffic mirroring is a native feature for some network devices and used for network analysis and may be configured to duplicate traffic and forward to one or more destinations for analysis by a network analyzer or other monitoring device. 
Adversaries may abuse traffic mirroring to mirror or redirect network traffic through other network infrastructure they control. Malicious modifications to network devices to enable traffic redirection may be possible through ROMMONkit or Patch System Image. Adversaries may use traffic duplication in conjunction with Network Sniffing, Input Capture, or Adversary-in-the-Middle depending on the goals and objectives of the adversary.
|M1041||Encrypt Sensitive Information||
Ensure that all wired and/or wireless traffic is encrypted appropriately. Use best practices for authentication protocols, such as Kerberos, and ensure web traffic that may contain credentials is protected by SSL/TLS.
|ID||Data Source||Data Component||Detects|
|DS0029||Network Traffic||Network Connection Creation||
Monitor for newly constructed network connections that are sent or received by abnormal or untrusted hosts.
|Network Traffic Flow||
Monitor and analyze network flows associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, or gratuitous or anomalous traffic patterns). Consider analyzing newly constructed network connections that are sent or received by untrusted hosts, unexpcted hardware devices, or other uncommon data flows.