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MITRE ATT&CK® Technique

T1021.005: VNC

Adversaries may use Valid Accounts to remotely control machines using Virtual Network Computing (VNC). VNC is a platform-independent desktop sharing system that uses the RFB (“remote framebuffer”) protocol to enable users to remotely control another computer’s display by relaying the screen, mouse, and keyboard inputs over the network.[1]

VNC differs from Remote Desktop Protocol as VNC is screen-sharing software rather than resource-sharing software. By default, VNC uses the system's authentication, but it can be configured to use credentials specific to VNC.[2][3]

Adversaries may abuse VNC to perform malicious actions as the logged-on user such as opening documents, downloading files, and running arbitrary commands. An adversary could use VNC to remotely control and monitor a system to collect data and information to pivot to other systems within the network. Specific VNC libraries/implementations have also been susceptible to brute force attacks and memory usage exploitation.[4][5][6][7][8][9]

EnterpriseT1021.005Sub-techniqueObject v1.2Modified
Glexia's Take · Automated analysis

Security context for executives and security teams

Automation confidenceHigh

VNC matters because it can turn a valid login into full interactive control of a workstation or server across Windows, Linux, and macOS. For leaders, the risk is not just “remote access exists”; it is whether the organization can prove VNC is approved, patched, restricted, logged, and distinguishable from unauthorized screen-control activity during an incident.

Executive priority

Prioritize this where remote administration is allowed, where shared desktops support operations, or where high-value systems could be controlled as a logged-on user. Governance questions should include: which VNC implementations are approved, who may use them, whether VNC-specific credentials exist outside centralized identity controls, whether lateral VNC traffic is filtered, and whether audit evidence can show unauthorized remote-control sessions. This supports resilience, compliance readiness, and incident decision-making because VNC abuse can enable hands-on actions such as opening documents, downloading files, running commands, monitoring users, and pivoting further inside the network.

Technical view

ATT&CK places VNC under Remote Services for lateral movement. The supplied description ties the behavior to Valid Accounts and the RFB remote framebuffer protocol, with platform scope across Linux, Windows, and macOS. Because MITRE provides no official detection text, SOC and detection engineering teams should validate coverage against the related detection strategy DET0178, “Behavioral Detection of Unauthorized VNC Remote Control Sessions,” and build local logic around authorized-use baselines, unexpected VNC services, remote-control session evidence, authentication events, and lateral network connections. IR teams should treat observed VNC activity as both an identity question and an endpoint-control question: determine the account used, whether authentication was system-based or VNC-specific, what host was controlled, and what user-context actions occurred during the session.

Likely telemetry

  • Network flow and firewall logs showing RFB/VNC remote-control connections between hosts
  • Endpoint service, process, and installed-software inventory identifying VNC servers or clients
  • Authentication logs for system accounts and any VNC-specific credential mechanisms
  • Session or remote-login records, including macOS unified log evidence where available
  • Endpoint activity around files opened, downloads, commands run, and interactive user-context actions during remote-control windows

Detection direction

  • Create an allowlist of approved VNC use cases, servers, administrators, and source networks; alert on deviations rather than treating all screen sharing as malicious.
  • Correlate VNC/RFB network activity with successful authentication, endpoint process/service state, and expected change or support tickets to reduce false positives from legitimate administration.
  • Hunt for newly enabled VNC services, unapproved VNC software, or VNC-specific credentials that bypass normal identity governance.
  • Review lateral movement context: VNC use after suspicious credential activity or from unusual internal hosts should receive higher priority.
  • Account for blind spots: MITRE provides no official detection procedure for this technique, and visibility can be weak if network logs lack east-west coverage, endpoints do not record service state, or VNC authentication is separate from centralized system authentication.

Mitigation priorities

  • First, remove or disable unnecessary VNC services and remote-control features, aligning with M1042 Disable or Remove Feature or Program.
  • Second, restrict installation of unauthorized VNC tools using software control and least-privilege practices, aligning with M1033 Limit Software Installation.
  • Third, filter ingress, egress, and lateral VNC traffic so only approved administrative paths are allowed, aligning with M1037 Filter Network Traffic.
  • Fourth, audit VNC configuration, authentication mode, enabled services, installed versions, and usage history, aligning with M1047 Audit.
  • Finally, include VNC in incident response playbooks: validate account exposure, session timeline, controlled host actions, and whether further pivoting occurred.
Additional notes and limits

This technique is a sub-technique of T1021 Remote Services and is specifically scoped to VNC-based remote control over Linux, Windows, and macOS. The object highlights Valid Accounts, possible use of system authentication or VNC-specific credentials, and historical concerns around brute force and implementation vulnerabilities. Relationship context includes one detection strategy, four mitigations, and several groups/software entries that use the technique; these support prioritization but should not be interpreted as evidence of activity in any given environment.

No official MITRE detection text is supplied for this object. The ATT&CK fields do not provide vendor-specific log sources, default ports, analytic logic, or guaranteed indicators. Local environment data is required to distinguish approved remote administration from unauthorized VNC control and to assess exposure to specific VNC implementations or vulnerabilities.

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

Official MITRE ATT&CK definition

VNC

Adversaries may use Valid Accounts to remotely control machines using Virtual Network Computing (VNC). VNC is a platform-independent desktop sharing system that uses the RFB (“remote framebuffer”) protocol to enable users to remotely control another computer’s display by relaying the screen, mouse, and keyboard inputs over the network.[1]

VNC differs from Remote Desktop Protocol as VNC is screen-sharing software rather than resource-sharing software. By default, VNC uses the system's authentication, but it can be configured to use credentials specific to VNC.[2][3]

Adversaries may abuse VNC to perform malicious actions as the logged-on user such as opening documents, downloading files, and running arbitrary commands. An adversary could use VNC to remotely control and monitor a system to collect data and information to pivot to other systems within the network. Specific VNC libraries/implementations have also been susceptible to brute force attacks and memory usage exploitation.[4][5][6][7][8][9]

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.

ATT&CK relationship table

Related techniques

This mirrors the MITRE pattern of making group, software, campaign, and technique relationships scannable. Relationship notes come from mirrored ATT&CK relationship text when available.

1 rows
DomainIDNameRelationship / procedure
EnterpriseT1021Remote ServicesThis object subtechnique of Remote Services.
Associated objects

Groups, software, and campaigns

GroupEnterprise

G0047: Gamaredon Group

Gamaredon Group is a suspected Russian cyber espionage group that has targeted military, law enforcement, judiciary, non-profit, and non-governmental organizations in Ukraine since at least 2013. The name Gamaredon Group derives from a misspelling of the word "Armageddon," found in early campaigns.[1][2][3][4][5]

In November 2021, the Ukrainian government publicly attributed Gamaredon Group to Russia’s Federal Security Service (FSB) Center 18, an assessment later supported by multiple independent cybersecurity researchers. [6][5]

GroupEnterprise

G0046: FIN7

FIN7 is a financially-motivated threat group that has been active since 2013. FIN7 has targeted the retail, restaurant, hospitality, software, consulting, financial services, medical equipment, cloud services, media, food and beverage, transportation, pharmaceutical, and utilities industries in the United States. A portion of FIN7 was operated out of a front company called Combi Security and often used point-of-sale malware for targeting efforts. Since 2020, FIN7 shifted operations to big game hunting (BGH), including use of REvil ransomware and their own Ransomware-as-a-Service (RaaS), Darkside. FIN7 may be linked to the Carbanak Group, but multiple threat groups have been observed using Carbanak, leading these groups to be tracked separately.[1][2][3][4][5][6][7]

GroupEnterprise

G0036: GCMAN

GCMAN is a threat group that focuses on targeting banks for the purpose of transferring money to e-currency services. [1]

GroupEnterprise

G0117: Fox Kitten

Fox Kitten is threat actor with a suspected nexus to the Iranian government that has been active since at least 2017 against entities in the Middle East, North Africa, Europe, Australia, and North America. Fox Kitten has targeted multiple industrial verticals including oil and gas, technology, government, defense, healthcare, manufacturing, and engineering.[1][2][3][4]

MalwareEnterprise

S0412: ZxShell

ZxShell is a remote administration tool and backdoor that can be downloaded from the Internet, particularly from Chinese hacker websites. It has been used since at least 2004.[1][2]

Windows
MalwareEnterprise

S0484: Carberp

Carberp is a credential and information stealing malware that has been active since at least 2009. Carberp's source code was leaked online in 2013, and subsequently used as the foundation for the Carbanak backdoor.[1][2][3]

Windows
MalwareEnterprise

S0266: TrickBot

TrickBot is a Trojan spyware program written in C++ that first emerged in September 2016 as a possible successor to Dyre. TrickBot was developed and initially used by Wizard Spider for targeting banking sites in North America, Australia, and throughout Europe; it has since been used against all sectors worldwide as part of "big game hunting" ransomware campaigns.[1][2][3][4]

Windows
MalwareEnterprise

S0670: WarzoneRAT

WarzoneRAT is a malware-as-a-service remote access tool (RAT) written in C++ that has been publicly available for purchase since at least late 2018.[1][2]

Windows
MalwareEnterprise

S1160: Latrodectus

Latrodectus is a Windows malware downloader that has been used since at least 2023 to download and execute additional payloads and modules. Latrodectus has most often been distributed through email campaigns, primarily by TA577 and TA578, and has infrastructure overlaps with historic IcedID operations.[1][2][3]

Windows
Relationship explorer

All related ATT&CK context

Mitigations

Mitigation direction

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
19.1
Object version
1.2
Created
Modified
Raw hash
a582787ba852cd72...
Imported snapshots across ATT&CK releases(1)
ReleaseBundle importedObject versionModifiedStatusRaw hash
19.11.2Current bundlea582787ba852…
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.

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. [1]
    The Remote Framebuffer Protocol

    T. Richardson, J. Levine, RealVNC Ltd.. (2011, March). The Remote Framebuffer Protocol. Retrieved September 20, 2021.

    Open source URL
  2. [2]
    MacOS VNC software for Remote Desktop

    Apple Support. (n.d.). Set up a computer running VNC software for Remote Desktop. Retrieved August 18, 2021.

    Open source URL
  3. [3]
    VNC Authentication

    Tegan. (2019, August 15). Setting up System Authentication. Retrieved September 20, 2021.

    Open source URL
  4. [4]
    Hijacking VNC

    Z3RO. (2019, March 10). Day 70: Hijacking VNC (Enum, Brute, Access and Crack). Retrieved September 20, 2021.

    Open source URL
  5. [5]
    macOS root VNC login without authentication

    Nick Miles. (2017, November 30). Detecting macOS High Sierra root account without authentication. Retrieved September 20, 2021.

    Open source URL
  6. [6]
    VNC Vulnerabilities

    Sergiu Gatlan. (2019, November 22). Dozens of VNC Vulnerabilities Found in Linux, Windows Solutions. Retrieved September 20, 2021.

    Open source URL
  7. [7]
    Offensive Security VNC Authentication Check

    Offensive Security. (n.d.). VNC Authentication. Retrieved October 6, 2021.

    Open source URL
  8. [8]
    Attacking VNC Servers PentestLab

    Administrator, Penetration Testing Lab. (2012, October 30). Attacking VNC Servers. Retrieved October 6, 2021.

    Open source URL
  9. [9]
    Havana authentication bug

    Jay Pipes. (2013, December 23). Security Breach! Tenant A is seeing the VNC Consoles of Tenant B!. Retrieved September 12, 2024.

    Open source URL
  10. [10]
    Talos ZxShell Oct 2014

    Allievi, A., et al. (2014, October 28). Threat Spotlight: Group 72, Opening the ZxShell. Retrieved September 24, 2019.

    Open source URL
  11. [11]
    Symantec Shuckworm January 2022

    Symantec. (2022, January 31). Shuckworm Continues Cyber-Espionage Attacks Against Ukraine. Retrieved February 17, 2022.

    Open source URL
  12. [12]
    Microsoft Actinium February 2022

    Microsoft Threat Intelligence Center. (2022, February 4). ACTINIUM targets Ukrainian organizations. Retrieved February 18, 2022.

    Open source URL
  13. [13]
    Unit 42 Gamaredon February 2022

    Unit 42. (2022, February 3). Russia’s Gamaredon aka Primitive Bear APT Group Actively Targeting Ukraine. Retrieved February 21, 2022.

    Open source URL
  14. [14]
    CrowdStrike Carbon Spider August 2021

    Loui, E. and Reynolds, J. (2021, August 30). CARBON SPIDER Embraces Big Game Hunting, Part 1. Retrieved September 20, 2021.

    Open source URL
  15. [15]
    ClearSky Siamesekitten August 2021

    ClearSky Cyber Security . (2021, August). New Iranian Espionage Campaign By “Siamesekitten” - Lyceum. Retrieved June 6, 2022.

    Open source URL
  16. [16]
    Prevx Carberp March 2011

    Giuliani, M., Allievi, A. (2011, February 28). Carberp - a modular information stealing trojan. Retrieved September 12, 2024.

    Open source URL
  17. [17]
    Securelist GCMAN

    Kaspersky Lab's Global Research & Analysis Team. (2016, February 8). APT-style bank robberies increase with Metel, GCMAN and Carbanak 2.0 attacks. Retrieved April 20, 2016.

    Open source URL
  18. [18]
    CISA AA20-259A Iran-Based Actor September 2020

    CISA. (2020, September 15). Iran-Based Threat Actor Exploits VPN Vulnerabilities. Retrieved December 21, 2020.

    Open source URL
  19. [19]
    Trickbot VNC module July 2021

    Ionut Illascu. (2021, July 14). Trickbot updates its VNC module for high-value targets. Retrieved September 10, 2021.

    Open source URL
  20. [20]
    Bitdefender Trickbot VNC module Whitepaper 2021

    Radu Tudorica. (2021, July 12). A Fresh Look at Trickbot’s Ever-Improving VNC Module. Retrieved September 28, 2021.

    Open source URL
  21. [21]
    objsee mac malware 2017

    Patrick Wardle. (n.d.). Mac Malware of 2017. Retrieved September 21, 2018.

    Open source URL
  22. [22]
    Check Point Warzone Feb 2020

    Harakhavik, Y. (2020, February 3). Warzone: Behind the enemy lines. Retrieved December 17, 2021.

    Open source URL
  23. [23]
    Palo Alto Latrodectus Activity June 2024

    Unit 42. (2024, June 25). 2024-06-25-IOCs-from-Latrodectus-activity. Retrieved September 13, 2024.

    Open source URL
  24. [24]
    Apple Unified Log Analysis Remote Login and Screen Sharing

    Sarah Edwards. (2020, April 30). Analysis of Apple Unified Logs: Quarantine Edition [Entry 6] – Working From Home? Remote Logins. Retrieved August 19, 2021.

    Open source URL
  25. [25]
    Apple Unified Log Analysis Remote Login and Screen Sharing

    Sarah Edwards. (2020, April 30). Analysis of Apple Unified Logs: Quarantine Edition [Entry 6] – Working From Home? Remote Logins. Retrieved August 19, 2021.

    Open source URL
  26. [26]
    Apple Unified Log Analysis Remote Login and Screen Sharing

    Sarah Edwards. (2020, April 30). Analysis of Apple Unified Logs: Quarantine Edition [Entry 6] – Working From Home? Remote Logins. Retrieved August 19, 2021.

    Open source URL
  27. [27]
    Attacking VNC Servers PentestLab

    Administrator, Penetration Testing Lab. (2012, October 30). Attacking VNC Servers. Retrieved October 6, 2021.

    Open source URL
  28. [28]
    Attacking VNC Servers PentestLab

    Administrator, Penetration Testing Lab. (2012, October 30). Attacking VNC Servers. Retrieved October 6, 2021.

    Open source URL
  29. [29]
    Gnome Remote Desktop grd-settings

    Pascal Nowack. (n.d.). Retrieved September 21, 2021.

    Open source URL
  30. [30]
    Gnome Remote Desktop grd-settings

    Pascal Nowack. (n.d.). Retrieved September 21, 2021.

    Open source URL
  31. [31]
    Gnome Remote Desktop grd-settings

    Pascal Nowack. (n.d.). Retrieved September 21, 2021.

    Open source URL
  32. [32]
    Gnome Remote Desktop gschema

    Pascal Nowack. (n.d.). Retrieved September 21, 2021.

    Open source URL
  33. [33]
    Gnome Remote Desktop gschema

    Pascal Nowack. (n.d.). Retrieved September 21, 2021.

    Open source URL
  34. [34]
    Gnome Remote Desktop gschema

    Pascal Nowack. (n.d.). Retrieved September 21, 2021.

    Open source URL
  35. [35]
    Havana authentication bug

    Jay Pipes. (2013, December 23). Security Breach! Tenant A is seeing the VNC Consoles of Tenant B!. Retrieved September 12, 2024.

    Open source URL
  36. [36]
    Havana authentication bug

    Jay Pipes. (2013, December 23). Security Breach! Tenant A is seeing the VNC Consoles of Tenant B!. Retrieved September 12, 2024.

    Open source URL
  37. [37]
    Hijacking VNC

    Z3RO. (2019, March 10). Day 70: Hijacking VNC (Enum, Brute, Access and Crack). Retrieved September 20, 2021.

    Open source URL
  38. [38]
    Hijacking VNC

    Z3RO. (2019, March 10). Day 70: Hijacking VNC (Enum, Brute, Access and Crack). Retrieved September 20, 2021.

    Open source URL
  39. [39]
    MacOS VNC software for Remote Desktop

    Apple Support. (n.d.). Set up a computer running VNC software for Remote Desktop. Retrieved August 18, 2021.

    Open source URL
  40. [40]
    MacOS VNC software for Remote Desktop

    Apple Support. (n.d.). Set up a computer running VNC software for Remote Desktop. Retrieved August 18, 2021.

    Open source URL
  41. [41]
    Offensive Security VNC Authentication Check

    Offensive Security. (n.d.). VNC Authentication. Retrieved October 6, 2021.

    Open source URL
  42. [42]
    Offensive Security VNC Authentication Check

    Offensive Security. (n.d.). VNC Authentication. Retrieved October 6, 2021.

    Open source URL
  43. [43]
    The Remote Framebuffer Protocol

    T. Richardson, J. Levine, RealVNC Ltd.. (2011, March). The Remote Framebuffer Protocol. Retrieved September 20, 2021.

    Open source URL
  44. [44]
    The Remote Framebuffer Protocol

    T. Richardson, J. Levine, RealVNC Ltd.. (2011, March). The Remote Framebuffer Protocol. Retrieved September 20, 2021.

    Open source URL
  45. [45]
    VNC Authentication

    Tegan. (2019, August 15). Setting up System Authentication. Retrieved September 20, 2021.

    Open source URL
  46. [46]
    VNC Authentication

    Tegan. (2019, August 15). Setting up System Authentication. Retrieved September 20, 2021.

    Open source URL
  47. [47]
    VNC Vulnerabilities

    Sergiu Gatlan. (2019, November 22). Dozens of VNC Vulnerabilities Found in Linux, Windows Solutions. Retrieved September 20, 2021.

    Open source URL
  48. [48]
    VNC Vulnerabilities

    Sergiu Gatlan. (2019, November 22). Dozens of VNC Vulnerabilities Found in Linux, Windows Solutions. Retrieved September 20, 2021.

    Open source URL
  49. [49]
    macOS root VNC login without authentication

    Nick Miles. (2017, November 30). Detecting macOS High Sierra root account without authentication. Retrieved September 20, 2021.

    Open source URL
  50. [50]
    macOS root VNC login without authentication

    Nick Miles. (2017, November 30). Detecting macOS High Sierra root account without authentication. Retrieved September 20, 2021.

    Open source URL
  51. [51]
    mitre-attackT1021.005
    Open source URL
  52. [52]
    mitre-attackT1021.005
    Open source URL
  53. [53]
    mitre-attackT1021.005
    Open source URL
  54. [54]
    Talos ZxShell Oct 2014

    Allievi, A., et al. (2014, October 28). Threat Spotlight: Group 72, Opening the ZxShell. Retrieved September 24, 2019.

    Open source URL
  55. [55]
    Microsoft Actinium February 2022

    Microsoft Threat Intelligence Center. (2022, February 4). ACTINIUM targets Ukrainian organizations. Retrieved February 18, 2022.

    Open source URL
  56. [56]
    Symantec Shuckworm January 2022

    Symantec. (2022, January 31). Shuckworm Continues Cyber-Espionage Attacks Against Ukraine. Retrieved February 17, 2022.

    Open source URL
  57. [57]
    Unit 42 Gamaredon February 2022

    Unit 42. (2022, February 3). Russia’s Gamaredon aka Primitive Bear APT Group Actively Targeting Ukraine. Retrieved February 21, 2022.

    Open source URL
  58. [58]
    CrowdStrike Carbon Spider August 2021

    Loui, E. and Reynolds, J. (2021, August 30). CARBON SPIDER Embraces Big Game Hunting, Part 1. Retrieved September 20, 2021.

    Open source URL
  59. [59]
    ClearSky Siamesekitten August 2021

    ClearSky Cyber Security . (2021, August). New Iranian Espionage Campaign By “Siamesekitten” - Lyceum. Retrieved June 6, 2022.

    Open source URL
  60. [60]
    Prevx Carberp March 2011

    Giuliani, M., Allievi, A. (2011, February 28). Carberp - a modular information stealing trojan. Retrieved September 12, 2024.

    Open source URL
  61. [61]
    Securelist GCMAN

    Kaspersky Lab's Global Research & Analysis Team. (2016, February 8). APT-style bank robberies increase with Metel, GCMAN and Carbanak 2.0 attacks. Retrieved April 20, 2016.

    Open source URL
  62. [62]
    CISA AA20-259A Iran-Based Actor September 2020

    CISA. (2020, September 15). Iran-Based Threat Actor Exploits VPN Vulnerabilities. Retrieved December 21, 2020.

    Open source URL
  63. [63]
    Bitdefender Trickbot VNC module Whitepaper 2021

    Radu Tudorica. (2021, July 12). A Fresh Look at Trickbot’s Ever-Improving VNC Module. Retrieved September 28, 2021.

    Open source URL
  64. [64]
    Trickbot VNC module July 2021

    Ionut Illascu. (2021, July 14). Trickbot updates its VNC module for high-value targets. Retrieved September 10, 2021.

    Open source URL
  65. [65]
    objsee mac malware 2017

    Patrick Wardle. (n.d.). Mac Malware of 2017. Retrieved September 21, 2018.

    Open source URL
  66. [66]
    Check Point Warzone Feb 2020

    Harakhavik, Y. (2020, February 3). Warzone: Behind the enemy lines. Retrieved December 17, 2021.

    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.