Automated Exfiltration: Traffic Duplication
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 Man-in-the-Middle depending on the goals and objectives of the adversary.
|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.
Monitor network traffic for uncommon data flows (e.g. unusual network communications, suspicious communications that have never been seen before, communications sending fixed size data packets at regular intervals). Analyze packet contents to detect communications that do not follow the expected protocol behavior for the port that is being used.
- Cisco. (n.d.). Cisco IOS XR Interface and Hardware Component Configuration Guide for the Cisco CRS Router, Release 5.1.x. Retrieved October 19, 2020.
- Juniper. (n.d.). Understanding Port Mirroring on EX2200, EX3200, EX3300, EX4200, EX4500, EX4550, EX6200, and EX8200 Series Switches. Retrieved October 19, 2020.