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T0886 Remote Services

Adversaries may leverage remote services to move between assets and network segments. These services are often used to allow operators to interact with systems remotely within the network, some examples are RDP, SMB, SSH, and other similar mechanisms. 1 3 4

Remote services could be used to support remote access, data transmission, authentication, name resolution, and other remote functions. Further, remote services may be necessary to allow operators and administrators to configure systems within the network from their engineering or management workstations. An adversary may use this technique to access devices which may be dual-homed 1 to multiple network segments, and can be used for Program Download or to execute attacks on control devices directly through Valid Accounts.

Specific remote services (RDP & VNC) may be a precursor to enable Graphical User Interface execution on devices such as HMIs or engineering workstation software.

Based on incident data, CISA and FBI assessed that Chinese state-sponsored actors also compromised various authorized remote access channels, including systems designed to transfer data and/or allow access between corporate and ICS networks. 2

Item Value
ID T0886
Sub-techniques
Tactics TA0108, TA0109
Platforms Control Server, Engineering Workstation, Human-Machine Interface
Version 1.1
Created 12 April 2021
Last Modified 09 March 2023

Procedure Examples

ID Name Description
C0025 2016 Ukraine Electric Power Attack During the 2016 Ukraine Electric Power Attack, Sandworm Team used MS-SQL access to a pivot machine, allowing code execution throughout the ICS network.11
S1045 INCONTROLLER INCONTROLLER can use the CODESYS protocol to remotely connect to Schneider PLCs and perform maintenance functions on the device.8
C0009 Oldsmar Treatment Plant Intrusion During the Oldsmar Treatment Plant Intrusion, the threat actors gained access to the system through remote access software, allowing for the use of the standard operator HMI interface.12
S0496 REvil REvil uses the SMB protocol to encrypt files located on remotely connected file shares. 6
S0603 Stuxnet Stuxnet executes malicious SQL commands in the WinCC database server to propagate to remote systems. The malicious SQL commands include xp_cmdshell, sp_dumpdbilog, and sp_addextendedproc. 10
G0088 TEMP.Veles TEMP.Veles utilized remote desktop protocol (RDP) jump boxes to move into the ICS environment. 3

Mitigations

ID Mitigation Description
M0801 Access Management Access Management technologies can help enforce authentication on critical remote service, examples include, but are not limited to, device management services (e.g., telnet, SSH), data access servers (e.g., HTTP, Historians), and HMI sessions (e.g., RDP, VNC).
M0800 Authorization Enforcement Provide privileges corresponding to the restriction of a GUI session to control system operations (examples include HMI read-only vs. read-write modes). Ensure local users, such as operators and engineers, are giving prioritization over remote sessions and have the authority to regain control over a remote session if needed. Prevent remote access sessions (e.g., RDP, VNC) from taking over local sessions, especially those used for ICS control, especially HMIs.
M0937 Filter Network Traffic Filter application-layer protocol messages for remote services to block any unauthorized activity.
M0804 Human User Authentication All remote services should require strong authentication before providing user access.
M0807 Network Allowlists Network allowlists can be implemented through either host-based files or system host files to specify what external connections (e.g., IP address, MAC address, port, protocol) can be made from a device.
M0930 Network Segmentation Segment and control software movement between business and OT environments by way of one directional DMZs. Web access should be restricted from the OT environment. Engineering workstations, including transient cyber assets (TCAs) should have minimal connectivity to external networks, including Internet and email, further limit the extent to which these devices are dual-homed to multiple networks. 5
M0927 Password Policies Enforce strong password requirements to prevent password brute force methods for lateral movement.
M0813 Software Process and Device Authentication All communication sessions to remote services should be authenticated to prevent unauthorized access.
M0918 User Account Management Limit the accounts that may use remote services. Limit the permissions for accounts that are at higher risk of compromise; for example, configure SSH so users can only run specific programs.

Detection

ID Data Source Data Component
DS0017 Command Command Execution
DS0028 Logon Session Logon Session Creation
DS0011 Module Module Load
DS0033 Network Share Network Share Access
DS0029 Network Traffic Network Connection Creation
DS0009 Process Process Creation

References

  1. Blake Johnson, Dan Caban, Marina Krotofil, Dan Scali, Nathan Brubaker, Christopher Glyer 2017, December 14 Attackers Deploy New ICS Attack Framework TRITON and Cause Operational Disruption to Critical Infrastructure Retrieved. 2018/01/12  ↩↩

  2. Department of Justice (DOJ), DHS Cybersecurity & Infrastructure Security Agency (CISA) 2021, July 20 Chinese Gas Pipeline Intrusion Campaign, 2011 to 2013 Retrieved. 2021/10/08  ↩

  3. Dragos 2017, December 13 TRISIS Malware Analysis of Safety System Targeted Malware Retrieved. 2018/01/12  ↩↩

  4. Joe Slowik 2019, April 10 Implications of IT Ransomware for ICS Environments Retrieved. 2019/10/27  ↩

  5. North America Transmission Forum 2019, December NATF Transient Cyber Asset Guidance Retrieved. 2020/09/25  ↩

  6. Max Heinemeyer 2020, February 21 Post-mortem of a targeted Sodinokibi ransomware attack Retrieved. 2021/04/12  ↩

  7. DRAGOS. (2022, April 13). Pipedream: Chernovite’s Emerging Malware Targeting Industrial Control Systems. Retrieved September 28, 2022. ↩

  8. Jimmy Wylie. (2022, August). Analyzing PIPEDREAM: Challenges in Testing an ICS Attack Toolkit. Defcon 30. ↩

  9. Nathan Brubaker, Keith Lunden, Ken Proska, Muhammad Umair, Daniel Kapellmann Zafra, Corey Hildebrandt, Rob Caldwell. (2022, April 13). INCONTROLLER: New State-Sponsored Cyber Attack Tools Target Multiple Industrial Control Systems. Retrieved September 28, 2022. ↩

  10. Nicolas Falliere, Liam O Murchu, Eric Chien 2011, February W32.Stuxnet Dossier (Version 1.4) Retrieved. 2017/09/22  ↩

  11. Joe Slowik. (2018, October 12). Anatomy of an Attack: Detecting and Defeating CRASHOVERRIDE. Retrieved December 18, 2020. ↩

  12. Pinellas County Sheriffs Office 2021, February 8 Treatment Plant Intrusion Press Conference Retrieved. 2021/10/08  ↩