T1040: Network Sniffing

T1040: Network Sniffing describes 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 cr...

Executive priority

T1040: Network Sniffing is an official MITRE ATT&CK technique. Glexia treats it as defensive behavior context for prioritizing monitoring, control validation, and response planning without using the object by itself as an attribution claim.

Technical view

Security teams should validate T1040: Network Sniffing by reviewing the official ATT&CK relationships, mapped tactics (credential-access, discovery), supported platforms (IaaS, Linux, macOS, Network Devices), and available local telemetry before making detection or mitigation decisions.

Likely telemetry

Official ATT&CK relationships and object metadata
Identity, privilege, and authentication events
Endpoint process, command-line, and script execution logs
Cloud control-plane, SaaS audit, and container platform logs
Network, endpoint, and security-tool telemetry

Detection direction

Validate whether T1040: Network Sniffing appears in your detection coverage and tabletop scenarios.
Use the object to align executive risk language with SOC, incident response, and detection engineering work.
Do not treat ATT&CK relationship context as attribution without corroborating evidence.

Mitigation priorities

Map the object to existing controls and identify missing telemetry or response ownership.
Prioritize mitigations that reduce exposure on the listed platforms and tactics.
Review adjacent ATT&CK relationships before changing policy, detections, or reporting language.

Additional notes and limits

Baseline Glexia take generated from the official MITRE ATT&CK STIX object, source hash, tactics, platforms, and detection fields. It is safe to replace with a richer model-generated take for the same source hash later.

This baseline take is source-grounded and schema-validated, but it does not include environment-specific telemetry, incident evidence, or threat-intelligence corroboration.

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Official MITRE ATT&CK definition

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.[1][2][3] 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.[4][5] The adversary can then use exfiltration techniques such as Transfer Data to Cloud Account in order to access the sniffed traffic.[4]

On network devices, adversaries may perform network captures using Network Device CLI commands such as `monitor capture`.[6][7]

View the same entry on attack.mitre.org (MITRE-hosted reference; in-page links above use the Glexia ATT&CK library.)

Glexia analysis

How security teams should use this page

Treat this object as behavior context, not an attribution claim. Validate the related groups, software, data sources, and mitigations against official ATT&CK relationships and your own telemetry before making control-coverage decisions.

Associated objects

Groups, software, and campaigns

G0094: Kimsuky

Kimsuky is a Democratic People's Republic of Korea (DPRK)-based cyber espionage group that has been active since at least 2012. The group initially targeted South Korean government agencies, think tanks, and subject-matter experts in various fields. Its operations expanded to include the United Nations and organizations in the government, education, business services, and manufacturing sectors across the United States, Japan, Russia, and Europe. Kimsuky has focused collection on foreign policy and national security issues tied to the Korean Peninsula, nuclear policy, and sanctions. Kimsuky operations have overlapped with those of other North Korean state-sponsored cyber espionage actors as a result of ad hoc collaborations or other limited resource sharing.[1][2][3][4][5][6]

Kimsuky was assessed to be responsible for the 2014 Korea Hydro & Nuclear Power Co. compromise; other notable campaigns include Operation STOLEN PENCIL (2018), Operation Kabar Cobra (2019), and Operation Smoke Screen (2019).[7][8][9] In 2023, Kimsuky was observed using commercial large language models (LLMs) to assist with vulnerability research, scripting, social engineering and reconnaissance.[10]

DPRK threat actor cluster boundaries overlap in open source reporting, with some security researchers consolidating all attributed North Korean state-sponsored cyber activity under Lazarus Group, rather than tracking operationally distinct subgroups.

G1045: Salt Typhoon

Salt Typhoon is a People's Republic of China (PRC) state-backed actor that has been active since at least 2019 and responsible for numerous compromises of network infrastructure at major U.S. telecommunication and internet service providers (ISP).[1][2]

G0034: Sandworm Team

Sandworm Team is a destructive threat group that has been attributed to Russia's General Staff Main Intelligence Directorate (GRU) Main Center for Special Technologies (GTsST) military unit 74455.[1][2] This group has been active since at least 2009.[3][4][5][6]

In October 2020, the US indicted six GRU Unit 74455 officers associated with Sandworm Team for the following cyber operations: the 2015 and 2016 attacks against Ukrainian electrical companies and government organizations, the 2017 worldwide NotPetya attack, targeting of the 2017 French presidential campaign, the 2018 Olympic Destroyer attack against the Winter Olympic Games, the 2018 operation against the Organisation for the Prohibition of Chemical Weapons, and attacks against the country of Georgia in 2018 and 2019.[1][2] Some of these were conducted with the assistance of GRU Unit 26165, which is also referred to as APT28.[7]

G1048: UNC3886

UNC3886 is a China-nexus cyberespionage group that has been active since at least 2022, targeting defense, technology, and telecommunication organizations located in the United States and the Asia-Pacific-Japan (APJ) regions. UNC3886 has displayed a deep understanding of edge devices and virtualization technologies through the exploitation of zero-day vulnerabilities and the use of novel malware families and utilities.[1][2]

G0105: DarkVishnya

DarkVishnya is a financially motivated threat actor targeting financial institutions in Eastern Europe. In 2017-2018 the group attacked at least 8 banks in this region.[1]

G0007: APT28

APT28 is a threat group that has been attributed to Russia's General Staff Main Intelligence Directorate (GRU) 85th Main Special Service Center (GTsSS) military unit 26165.[1][2] This group has been active since at least 2004.[3][4][5][6][7][8][9][10][11][12][13]

APT28 reportedly compromised the Hillary Clinton campaign, the Democratic National Committee, and the Democratic Congressional Campaign Committee in 2016 in an attempt to interfere with the U.S. presidential election.[5] In 2018, the US indicted five GRU Unit 26165 officers associated with APT28 for cyber operations (including close-access operations) conducted between 2014 and 2018 against the World Anti-Doping Agency (WADA), the US Anti-Doping Agency, a US nuclear facility, the Organization for the Prohibition of Chemical Weapons (OPCW), the Spiez Swiss Chemicals Laboratory, and other organizations.[14] Some of these were conducted with the assistance of GRU Unit 74455, which is also referred to as Sandworm Team.

G1047: Velvet Ant

Velvet Ant is a threat actor operating since at least 2021. Velvet Ant is associated with complex persistence mechanisms, the targeting of network devices and appliances during operations, and the use of zero day exploits.[1][2]

G0064: APT33

APT33 is a suspected Iranian threat group that has carried out operations since at least 2013. The group has targeted organizations across multiple industries in the United States, Saudi Arabia, and South Korea, with a particular interest in the aviation and energy sectors.[1][2]

S1204: cd00r

cd00r is an open-source backdoor for UNIX and UNIX-variant operating systems that was orginally released in 2000. cd00r source code is primarily based on a packet-capturing program as it utilizes a sniffer to listen for specific sequences of network traffic or "secret knock" before executing the attacker's code.[1][2]

Network Devices

S1206: JumbledPath

JumbledPath is a custom-built utility written in GO that has been used by Salt Typhoon since at least 2024 for packet capture on remote Cisco devices. JumbledPath is compiled as an ELF binary using x86-64 architecture which makes it potentially useable across Linux operating systems and network devices from multiple vendors.[1]

Network Devices

S1154: VersaMem

VersaMem is a web shell designed for deployment to Versa Director servers following exploitation. Discovered in August 2024, VersaMem was used during Versa Director Zero Day Exploitation by Volt Typhoon to target ISPs and MSPs. VersaMem is deployed as a Java Archive (JAR) and allows for credential capture for Versa Director logon activity as well as follow-on execution of arbitrary Java payloads.[1]

Network Devices

S1224: CASTLETAP

CASTLETAP is an ICMP port knocking backdoor that has been installed on compromised FortiGate firewalls by UNC3886.[1]

Network Devices

S1203: J-magic

J-magic is a custom variant of the cd00r backdoor tailored to target Juniper routers that was first observed during the J-magic Campaign in mid-2023. J-magic monitors TCP traffic for five predefined parameters or "magic packets" to be sent by the attackers before activating on compromised devices.[1]

Network Devices

S0367: Emotet

Emotet is a modular malware variant which is primarily used as a downloader for other malware variants such as TrickBot and IcedID. Emotet first emerged in June 2014, initially targeting the financial sector, and has expanded to multiple verticals over time.[1]

Windows

S0019: Regin

Regin is a malware platform that has targeted victims in a range of industries, including telecom, government, and financial institutions. Some Regin timestamps date back to 2003. [1]

Windows

S1186: Line Dancer

Line Dancer is a memory-only Lua-based shellcode loader associated with the ArcaneDoor campaign. Line Dancer allows an adversary to upload and execute arbitrary shellcode on victim devices.[1][2]

Network Devices

S0661: FoggyWeb

FoggyWeb is a passive and highly-targeted backdoor capable of remotely exfiltrating sensitive information from a compromised Active Directory Federated Services (AD FS) server. It has been used by APT29 since at least early April 2021.[1]

Windows

S0443: MESSAGETAP

MESSAGETAP is a data mining malware family deployed by APT41 into telecommunications networks to monitor and save SMS traffic from specific phone numbers, IMSI numbers, or that contain specific keywords. [1]

Linux

S0587: Penquin

Penquin is a remote access trojan (RAT) with multiple versions used by Turla to target Linux systems since at least 2014.[1][2]

Linux

S9024: SPAWNCHIMERA

SPAWNCHIMERA is a backdoor that supports command and control and can inject malicious components into native processes.[1][2][3] SPAWNCHIMERA It incorporates capabilities from multiple tools within the SPAWN malware family, including SPAWNANT, SPAWNMOLE, and SPAWNSNAIL.[4][2][3] SPAWNCHIMERA was first reported in April 2024.[2] SPAWNCHIMERA has been observed in activity attributed to People's Republic of China (PRC) state-sponsored threat actors, including UNC5221..[4][5][2][6]

LinuxNetwork Devices

C0056: RedPenguin

The RedPenguin project was launched by Juniper in July 2024 to investigate reported malware infections of Juniper MX Series routers. RedPenguin activity was separately attributed to UNC3886 and included the deployment of multiple custom versions of the publicly-available TINYSHELL backdoor on Juniper routers.[1][2]

C0028: 2015 Ukraine Electric Power Attack

2015 Ukraine Electric Power Attack was a Sandworm Team campaign during which they used BlackEnergy (specifically BlackEnergy3) and KillDisk to target and disrupt transmission and distribution substations within the Ukrainian power grid. This campaign was the first major public attack conducted against the Ukrainian power grid by Sandworm Team.

C0046: ArcaneDoor

ArcaneDoor is a campaign targeting networking devices from Cisco and other vendors between July 2023 and April 2024, primarily focused on government and critical infrastructure networks. ArcaneDoor is associated with the deployment of the custom backdoors Line Runner and Line Dancer. ArcaneDoor is attributed to a group referred to as UAT4356 or STORM-1849, and is assessed to be a state-sponsored campaign.[1][2]

Relationship explorer

All related ATT&CK context

Mitigations

Mitigation direction

M1030: Network Segmentation

Network segmentation involves dividing a network into smaller, isolated segments to control and limit the flow of traffic between devices, systems, and applications. By segmenting networks, organizations can reduce the attack surface, restrict lateral movement by adversaries, and protect critical assets from compromise.

Effective network segmentation leverages a combination of physical boundaries, logical separation through VLANs, and access control policies enforced by network appliances like firewalls, routers, and cloud-based configurations. This mitigation can be implemented through the following measures:

Segment Critical Systems:

- Identify and group systems based on their function, sensitivity, and risk. Examples include payment systems, HR databases, production systems, and internet-facing servers. - Use VLANs, firewalls, or routers to enforce logical separation.

Implement DMZ for Public-Facing Services:

- Host web servers, DNS servers, and email servers in a DMZ to limit their access to internal systems. - Apply strict firewall rules to filter traffic between the DMZ and internal networks.

Use Cloud-Based Segmentation:

- In cloud environments, use VPCs, subnets, and security groups to isolate applications and enforce traffic rules. - Apply AWS Transit Gateway or Azure VNet peering for controlled connectivity between cloud segments.

Apply Microsegmentation for Workloads:

- Use software-defined networking (SDN) tools to implement workload-level segmentation and prevent lateral movement.

Restrict Traffic with ACLs and Firewalls:

- Apply Access Control Lists (ACLs) to network devices to enforce "deny by default" policies. - Use firewalls to restrict both north-south (external-internal) and east-west (internal-internal) traffic.

Monitor and Audit Segmented Networks:

- Regularly review firewall rules, ACLs, and segmentation policies. - Monitor network flows for anomalies to ensure segmentation is effective.

Test Segmentation Effectiveness:

- Perform periodic penetration tests to verify that unauthorized access is blocked between network segments.

M1018: User Account Management

User Account Management involves implementing and enforcing policies for the lifecycle of user accounts, including creation, modification, and deactivation. Proper account management reduces the attack surface by limiting unauthorized access, managing account privileges, and ensuring accounts are used according to organizational policies. This mitigation can be implemented through the following measures:

Enforcing the Principle of Least Privilege

- Implementation: Assign users only the minimum permissions required to perform their job functions. Regularly audit accounts to ensure no excess permissions are granted. - Use Case: Reduces the risk of privilege escalation by ensuring accounts cannot perform unauthorized actions.

Implementing Strong Password Policies

- Implementation: Enforce password complexity requirements (e.g., length, character types). Require password expiration every 90 days and disallow password reuse. - Use Case: Prevents adversaries from gaining unauthorized access through password guessing or brute force attacks.

Managing Dormant and Orphaned Accounts

- Implementation: Implement automated workflows to disable accounts after a set period of inactivity (e.g., 30 days). Remove orphaned accounts (e.g., accounts without an assigned owner) during regular account audits. - Use Case: Eliminates dormant accounts that could be exploited by attackers.

Account Lockout Policies

- Implementation: Configure account lockout thresholds (e.g., lock accounts after five failed login attempts). Set lockout durations to a minimum of 15 minutes. - Use Case: Mitigates automated attack techniques that rely on repeated login attempts.

Multi-Factor Authentication (MFA) for High-Risk Accounts

- Implementation: Require MFA for all administrative accounts and high-risk users. Use MFA mechanisms like hardware tokens, authenticator apps, or biometrics. - Use Case: Prevents unauthorized access, even if credentials are stolen.

Restricting Interactive Logins

- Implementation: Restrict interactive logins for privileged accounts to specific secure systems or management consoles. Use group policies to enforce logon restrictions. - Use Case: Protects sensitive accounts from misuse or exploitation.

*Tools for Implementation*

Built-in Tools:

- Microsoft Active Directory (AD): Centralized account management and RBAC enforcement. - Group Policy Object (GPO): Enforce password policies, logon restrictions, and account lockout policies.

Identity and Access Management (IAM) Tools:

- Okta: Centralized user provisioning, MFA, and SSO integration. - Microsoft Azure Active Directory: Provides advanced account lifecycle management, role-based access, and conditional access policies.

Privileged Account Management (PAM): - CyberArk, BeyondTrust, Thycotic: Manage and monitor privileged account usage, enforce session recording, and JIT access.

M1032: Multi-factor Authentication

Multi-Factor Authentication (MFA) enhances security by requiring users to provide at least two forms of verification to prove their identity before granting access. These factors typically include:

- *Something you know*: Passwords, PINs. - *Something you have*: Physical tokens, smartphone authenticator apps. - *Something you are*: Biometric data such as fingerprints, facial recognition, or retinal scans.

Implementing MFA across all critical systems and services ensures robust protection against account takeover and unauthorized access. This mitigation can be implemented through the following measures:

Identity and Access Management (IAM):

- Use IAM solutions like Azure Active Directory, Okta, or AWS IAM to enforce MFA policies for all user logins, especially for privileged roles. - Enable conditional access policies to enforce MFA for risky sign-ins (e.g., unfamiliar devices, geolocations). - Enable Conditional Access policies to only allow logins from trusted devices, such as those enrolled in Intune or joined via Hybrid/Entra.

Authentication Tools and Methods:

- Use authenticator applications such as Google Authenticator, Microsoft Authenticator, or Authy for time-based one-time passwords (TOTP). - Deploy hardware-based tokens like YubiKey, RSA SecurID, or smart cards for additional security. - Enforce biometric authentication for compatible devices and applications.

Secure Legacy Systems:

- Integrate MFA solutions with older systems using third-party tools like Duo Security or Thales SafeNet. - Enable RADIUS/NPS servers to facilitate MFA for VPNs, RDP, and other network logins.

Monitoring and Alerting:

- Use SIEM tools to monitor failed MFA attempts, login anomalies, or brute-force attempts against MFA systems. - Implement alerts for suspicious MFA activities, such as repeated failed codes or new device registrations.

Training and Policy Enforcement:

- Educate employees on the importance of MFA and secure authenticator usage. - Enforce policies that require MFA on all critical systems, especially for remote access, privileged accounts, and cloud applications.

M1041: Encrypt Sensitive Information

Protect sensitive information at rest, in transit, and during processing by using strong encryption algorithms. Encryption ensures the confidentiality and integrity of data, preventing unauthorized access or tampering. This mitigation can be implemented through the following measures:

Encrypt Data at Rest:

- Use Case: Use full-disk encryption or file-level encryption to secure sensitive data stored on devices. - Implementation: Implement BitLocker for Windows systems or FileVault for macOS devices to encrypt hard drives.

Encrypt Data in Transit:

- Use Case: Use secure communication protocols (e.g., TLS, HTTPS) to encrypt sensitive data as it travels over networks. - Implementation: Enable HTTPS for all web applications and configure mail servers to enforce STARTTLS for email encryption.

Encrypt Backups:

- Use Case: Ensure that backup data is encrypted both during storage and transfer to prevent unauthorized access. - Implementation: Encrypt cloud backups using AES-256 before uploading them to Amazon S3 or Google Cloud.

Encrypt Application Secrets:

- Use Case: Store sensitive credentials, API keys, and configuration files in encrypted vaults. - Implementation: Use HashiCorp Vault or AWS Secrets Manager to manage and encrypt secrets.

Database Encryption:

- Use Case: Enable Transparent Data Encryption (TDE) or column-level encryption in database management systems. - Implementation: Use MySQL’s built-in encryption features to encrypt sensitive database fields such as social security numbers.

Change history

Object version and sync metadata

The fields below describe the current mirrored snapshot. When Glexia retains multiple ATT&CK source imports, you can open the table to compare the same object across releases (hashes and MITRE timestamps). For MITRE’s own release notes and roadmap, see ATT&CK resources — Updates.

ATT&CK release: 19.2
Object version: 1.7
Created: May 31, 2017, 21:30 UTC (UTC+00:00)
Modified: May 12, 2026, 15:12 UTC (UTC+00:00)
Raw hash: 325a52d041f054f9...

Imported snapshots across ATT&CK releases(2)

Release	Bundle imported	Object version	Modified	Status	Raw hash
19.2	Aug 6, 2026, 02:58 UTC (UTC+00:00)	1.7	May 12, 2026, 15:12 UTC (UTC+00:00)	Current bundle	`325a52d041f0…`
19.1	Jul 14, 2026, 09:14 UTC (UTC+00:00)	1.7	May 12, 2026, 15:12 UTC (UTC+00:00)	Older bundle	`325a52d041f0…`

Raw source

Mirrored ATT&CK source object

The raw object is retained through the mirrored ATT&CK source bundle and object hash. The raw endpoint returns the exact object from the mirrored bundle when available.

Open mirrored raw JSON Open MITRE-hosted copy

Source references

External references and citations

MITRE external references are preserved separately from Glexia analysis so citations remain traceable to their original source records.

[1]
AWS Traffic Mirroring
Amazon Web Services. (n.d.). How Traffic Mirroring works. Retrieved March 17, 2022.
Open source URL
[2]
GCP Packet Mirroring
Google Cloud. (n.d.). Packet Mirroring overview. Retrieved March 17, 2022.
Open source URL
[3]
Azure Virtual Network TAP
Microsoft. (2022, February 9). Virtual network TAP. Retrieved March 17, 2022.
Open source URL
[4]
Rhino Security Labs AWS VPC Traffic Mirroring
Spencer Gietzen. (2019, September 17). Abusing VPC Traffic Mirroring in AWS. Retrieved March 17, 2022.
Open source URL
[5]
SpecterOps AWS Traffic Mirroring
Luke Paine. (2020, March 11). Through the Looking Glass — Part 1. Retrieved March 17, 2022.
Open source URL
[6]
US-CERT-TA18-106A
US-CERT. (2018, April 20). Alert (TA18-106A) Russian State-Sponsored Cyber Actors Targeting Network Infrastructure Devices. Retrieved October 19, 2020.
Open source URL
[7]
capture_embedded_packet_on_software
Cisco. (2022, August 17). Configure and Capture Embedded Packet on Software. Retrieved July 13, 2022.
Open source URL
[8]
mitre-attackT1040
Open source URL

Source and licensing

Source: MITRE ATT&CK®. © 2026 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation. MITRE ATT&CK and ATT&CK are registered trademarks of The MITRE Corporation. Glexia is not affiliated with or endorsed by MITRE.

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T1040: Network Sniffing

Security context for executives and security teams

Executive priority

Technical view

Likely telemetry

Detection direction

Mitigation priorities

Network Sniffing

How security teams should use this page

Groups, software, and campaigns

All related ATT&CK context

Mitigation direction

Object version and sync metadata

Mirrored ATT&CK source object

External references and citations