T1040 Network Sniffing

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. For example, AWS Traffic Mirroring, GCP Packet Mirroring, and Azure vTap allow users to define specified instances to collect traffic from and specified targets to send collected traffic to.(Citation: AWS Traffic Mirroring)(Citation: GCP Packet Mirroring)(Citation: Azure Virtual Network TAP) Often, much of this traffic will be in cleartext due to the use of TLS termination at the load balancer level to reduce the strain of encrypting and decrypting traffic.(Citation: Rhino Security Labs AWS VPC Traffic Mirroring)(Citation: SpecterOps AWS Traffic Mirroring) The adversary can then use exfiltration techniques such as Transfer Data to Cloud Account in order to access the sniffed traffic.(Citation: Rhino Security Labs AWS VPC Traffic Mirroring)

On network devices, adversaries may perform network captures using Network Device CLI commands such as monitor capture.(Citation: US-CERT-TA18-106A)(Citation: capture_embedded_packet_on_software)

View in MITRE ATT&CK®

VERIS Mappings

Capability ID Capability Description Mapping Type ATT&CK ID ATT&CK Name Notes
attribute.confidentiality.data_disclosure Confirmed or potential data disclosure related-to T1040 Network Sniffing

GCP Mappings

Capability ID Capability Description Mapping Type ATT&CK ID ATT&CK Name Notes
backup_and_dr_actifiogo Backup and DR-Actifio GO technique_scores T1040 Network Sniffing
Comments
Backup and DR-Actifio GO provides encryption in transit for data traveling between Actifio appliances and other systems during backup and recovery operations. Data is encrypted while it travels across the network, providing protection against Network Sniffing since adversaries would be unable to read encrypted traffic. However, this is only relevant when traffic is being backed up, which is a small amount of the time. This results in a score of Minimal.
References
certificate_authority_service Certificate Authority Service technique_scores T1040 Network Sniffing
Comments
This control may mitigate against Network Sniffing by providing certificates for internal endpoints and applications to use with asymmetric encryption. This control helps protect the issuing Certificate Authority with the use of Google's IAM and policy controls.
References
cloud_vpn Cloud VPN technique_scores T1040 Network Sniffing
Comments
Cloud VPN enables traffic traveling between the two networks, and it is encrypted by one VPN gateway and then decrypted by the other VPN gateway. This action protects users' data as it travels over the internet. This control may prevent adversaries from sniffing network traffic.
References
secret_manager Secret Manager technique_scores T1040 Network Sniffing
Comments
This control provides secure methods for accessing secrets and passwords. This can reduce the incidents of credentials and other authentication material being transmitted in clear-text or by insecure encryption methods. Any communication between applications or endpoints after access to Secret Manager may not be secure.
References
security_command_center Security Command Center technique_scores T1040 Network Sniffing
Comments
Using Web Security Scanner, SCC is able to detect when passwords are transmitted in cleartext. Adversaries may use this traffic mirroring services to sniff traffic and intercept unencrypted credentials. This technique was graded as partial due to the low protect coverage when transmitting passwords in clear-text and there is more information that could be gathered during a network sniffing attacks.
References