Technique.View on attack.mitre.org
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. 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. The adversary can then use exfiltration techniques such as Transfer Data to Cloud Account in order to access the sniffed traffic.
On network devices, adversaries may perform network captures using Network Device CLI commands such as `monitor capture`.
Rules on DetectionCode tagged with T1040.
| Rule | Level | Log source |
|---|---|---|
| Cisco Sniffing | medium | cisco / NULL |
| Harvesting Of Wifi Credentials Via Netsh.EXE | medium | windows / process_creation |
| New Network Trace Capture Started Via Netsh.EXE | medium | windows / process_creation |
| PktMon.EXE Execution | medium | windows / process_creation |
| Potential Network Sniffing Activity Using Network Tools | medium | windows / process_creation |
| Potential Packet Capture Activity Via Start-NetEventSession - ScriptBlock | medium | windows / ps_script |
| Windows Pcap Drivers | medium | windows / NULL |
| Network Sniffing - Linux | low | linux / NULL |
| Network Sniffing - MacOs | informational | macos / process_creation |
| Rule | Type | Risk | Data source |
|---|---|---|---|
| Cisco ASA - Packet Capture Activity | Anomaly | NULL | Cisco ASA Logs |
| Cisco SNMP Community String Configuration Changes | Anomaly | NULL | Cisco IOS Logs |
| Windows Network Sniffing Tool Executed | Anomaly | NULL | Sysmon EventID 1, Windows Event Log Security 4688, CrowdStrike ProcessRollup2 |
| Used by | Procedure example |
|---|---|
| GroupAPT28 | APT28 deployed the open source tool Responder to conduct NetBIOS Name Service poisoning, which captured usernames and hashed passwords that allowed access to legitimate credentials. APT28 close-access teams have used Wi-Fi pineapples to intercept Wi-Fi signals and user credentials. |
| GroupAPT33 | APT33 has used SniffPass to collect credentials by sniffing network traffic. |
| GroupDarkVishnya | DarkVishnya used network sniffing to obtain login data. |
| GroupKimsuky | Kimsuky has used the Nirsoft SniffPass network sniffer to obtain passwords sent over non-secure protocols. |
| GroupSalt Typhoon | Salt Typhoon has used a variety of tools and techniques to capture packet data between network interfaces. |
| GroupSandworm Team | Sandworm Team has used intercepter-NG to sniff passwords in network traffic. |
| GroupUNC3886 | UNC3886 has used the LOOKOVER sniffer to sniff TACACS+ authentication packets. |
| GroupVelvet Ant | Velvet Ant has used a custom tool, "VELVETTAP", to perform packet capture from compromised F5 BIG-IP devices. |
| Used by | Procedure example |
|---|---|
| MalwareCASTLETAP | CASTLETAP has the ability to create a raw promiscuous socket to sniff network traffic. |
| Malwarecd00r | cd00r can use the libpcap library to monitor captured packets for specifc sequences. |
| MalwareEmotet | Emotet has been observed to hook network APIs to monitor network traffic. |
| ToolEmpire | Empire can be used to conduct packet captures on target hosts. |
| MalwareFoggyWeb | FoggyWeb can configure custom listeners to passively monitor all incoming HTTP GET and POST requests sent to the AD FS server from the intranet/internet and intercept HTTP requests that match the custom URI patterns defined by the actor. |
| ToolImpacket | Impacket can be used to sniff network traffic via an interface or raw socket. |
| MalwareJ-magic | J-magic has a pcap listener function that can create an Extended Berkley Packet Filter (eBPF) on designated interfaces and ports. |
| MalwareJumbledPath | JumbledPath has the ability to perform packet capture on remote devices via actor-defined jump-hosts. |
| Used by | Procedure example |
|---|---|
| Campaign2015 Ukraine Electric Power Attack | During the 2015 Ukraine Electric Power Attack, Sandworm Team used BlackEnergy’s network sniffer module to discover user credentials being sent over the network between the local LAN and the power grid’s industrial control systems. |
| CampaignArcaneDoor | ArcaneDoor included network packet capture and sniffing for data collection in victim environments. |
| CampaignRedPenguin | During RedPenguin, UNC3886 used a passive backdoor to act as a libpcap-based packet sniffer. |
Data from MITRE ATT&CK® (Enterprise). ATT&CK® is a registered trademark of The MITRE Corporation.
