Network Sniffing

What the technique is

Adversaries may passively sniff network traffic to capture information about an environment, including authentication material passed over the network. Network sniffing refers to using the network interface on a system to monitor or capture information sent over a wired or wireless connection. An adversary may place a network interface into promiscuous mode to passively access data in transit over the network, or use span ports to capture a larger amount of data. Data captured via this technique may include user credentials, especially those sent over an insecure, unencrypted protocol. Techniques for name service resolution poisoning, such as Name Resolution Poisoning and SMB Relay, can also be used to capture credentials to websites, proxies, and internal systems by redirecting traffic to an adversary. Network sniffing may reveal configuration details, such as running services, version numbers, and other network characteristics (e.g. IP addresses, hostnames, VLAN IDs) necessary for subsequent Lateral Movement and/or Stealth activities. Adversaries may likely also utilize network sniffing during Adversary-in-the-Middle (AiTM) to passively gain additional knowledge about the environment. In cloud-based environments, adversaries may still be able to use traffic mirroring services to sniff network traffic from virtual machines. […]

What MITRE says you would watch

• AN0875

  Detects suspicious execution of network monitoring tools (e.g., Wireshark, tshark, Microsoft Message Analyzer), driver loading indicative of promiscuous mode, or non-admin user privilege escalation to access NICs for capture.

• AN0876

  Correlates interface mode changes to promiscuous with execution of sniffing tools like tcpdump, tshark, or custom pcap libraries. Detects abnormal NIC configurations and unauthorized sniffing from non-root sessions.

• AN0877

  Detects enabling of interface sniffing via packet capture tools or AppleScript triggering tcpdump. Leverages Unified Logs and process lineage to identify suspicious use of pfctl, tcpdump, or libpcap libraries.