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Tactic Technique Use  Detection/Mitigations Reconnaissance [TA0043] Gather Victim Identity Information: Credentials [T1589.001]

The threat actor harvested credentials of third-party commercial organizations by sending spearphishing emails that contained a PDF attachment. The PDF attachment contained a shortened URL that, when clicked, led users to a website that prompted the user for their email address and password.
The threat actor harvested credentials of Energy Sector targets by sending spearphishing emails with a malicious Microsoft Word document or links to the watering holes created on compromised third-party websites.

Note: this activity also applies to: 

  • Tactic: Reconnaissance [TA0043], Technique: Phishing for Information [T1598]:

Software Configuration: implement configuration changes to software (other than the operating system) to mitigate security risks associated to how the software operates.

User Training: train users to be aware of access or manipulation attempts by an adversary to reduce the risk of successful spearphishing, social engineering, and other techniques that involve user interaction.

Resource Development [TA0042] Compromise Infrastructure: Server [T1584.004] The threat actor created watering holes on compromised third-party organizations’ domains. This activity typically takes place outside the visibility of target organizations, making detection of this behavior difficult. Ensure that users browse the internet securely. Prevent intentional and unintentional download of malware or rootkits, and users from accessing infected or malicious websites. Treat all traffic as untrusted, even if it comes from a partner website or popular domain. Initial Access [TA0001] Valid Accounts [T1078] The threat actor obtained access to Energy Sector targets by leveraging compromised third-party infrastructure and previously compromised Energy Sector credentials against remote access services and infrastructure—specifically VPN, RDP, and Outlook Web Access—where MFA was not enabled.

Network Segmentation: architect sections of the network to isolate critical systems, functions, or resources. Use physical and logical segmentation to prevent access to potentially sensitive systems and information. Use a DMZ to contain any internet-facing services that should not be exposed from the internal network.

MFA: enforce use of two or more pieces of evidence (such as username and password plus a token, e.g., a physical smart card or token generator) to authenticate to a system.

Privileged Account Management: manage the creation of, modification of, use of, and permissions associated with privileged accounts, including SYSTEM and root.

Update Software: perform regular software updates to mitigate exploitation risk.

Exploit Protection: use capabilities to detect and block conditions that may lead to or be indicative of a software exploit occurring.

Application Isolation and Sandboxing: restrict execution of code to a virtual environment on or in transit to an endpoint system.

External Remote Services [T1133] The threat actor installed VPN clients on compromised third-party targets to connect to Energy Sector networks.

Network Segmentation: architect sections of the network to isolate critical systems, functions, or resources. Use physical and logical segmentation to prevent access to potentially sensitive systems and information. Use a DMZ to contain any internet-facing services that should not be exposed from the internal network.

MFA: enforce use of two or more pieces of evidence (such as username and password plus a token, e.g., a physical smart card or token generator) to authenticate to a system.

Limit Access to Resource Over Network: prevent access to file shares, remote access to systems, and unnecessary services. Mechanisms to limit access may include use of network concentrators, RDP gateways, etc.

Disable or Remove Program: remove or deny access to unnecessary and potentially vulnerable software to prevent abuse by adversaries.

Execution 
[TA0002] Command and Scripting Interpreter: PowerShell [T1059.001]

During an RDP session, the threat actor used a PowerShell Script to create an account within a victim’s Microsoft Exchange Server. 

Note: this activity also applies to: 

  • Tactic: Persistence [TA0003], Technique: Create Account: Local Account [T1136.001

Antivirus/Antimalware: use signatures or heuristics to detect malicious software.

Code Signing: enforce binary and application integrity with digital signature verification to prevent untrusted code from executing.

Disable or Remove Program: remove or deny access to unnecessary and potentially vulnerable software to prevent abuse by adversaries.

Privileged Account Management: manage the creation of, modification of, use of, and permissions associated with privileged accounts, including SYSTEM and root.

Command and Scripting Interpreter: Windows Command Shell [T1059.003]

The threat actor used a JavaScript with an embedded Command Shell script to:

  • Create a local administrator account; 
  • Disable the host-based firewall;
  • Globally open port 3389 for RDP access; and
  • Attempt to add the newly created account to the administrators group to gain elevated privileges. 

Note: this activity also applies to: 

  • Tactic: Credential Access [TA0006], Technique: Input Capture [T1056]
  • Tactic: Execution [TA0002], Technique: Command and Scripting Interpreter: JavaScript [T1059.007]
  • Tactic: Persistence [TA0003], Technique: Create Account: Local Account [T1136.001]
Execution Prevention: block execution of code on a system through application control, and/or script blocking. Scheduled Task/Job: Scheduled Task [T1053.005] The threat actor created a Scheduled Task to automatically log out of a newly created account every eight hours.

Audit: audit or scan systems, permissions, insecure software, insecure configurations, etc., to identify potential weaknesses.

Harden Operating System Configuration: make configuration changes related to the operating system or a common feature of the operating system that result in system hardening against techniques.

Privileged Account Management: manage the creation of, modification of, use of, and permissions associated with privileged accounts, including SYSTEM and root.

User Account Management: manage the creation of, modification of, use of, and permissions associated with user accounts.

Persistence [TA0003] Create Account: Local Account [T1136.001]  The threat actor created local administrator accounts on previously compromised third-party organizations for reconnaissance and to remotely access Energy Sector targets.    MFA: enforce use of two or more pieces of evidence (such as username and password plus a token, e.g., a physical smart card or token generator) to authenticate to a system.

MFA: enforce use of two or more pieces of evidence (such as username and password plus a token, e.g., a physical smart card or token generator) to authenticate to a system.

Privileged Account Management: manage the creation of, modification of, use of, and permissions associated with privileged accounts, including SYSTEM and root.

Server Software Component: Web Shell [T1505.003] The threat actor created webshells on Energy Sector targets’ publicly accessible email and web servers. Detect: the portion of the webshell that is on the server may be small and look innocuous. Process monitoring may be used to detect Web servers that perform suspicious actions such as running cmd.exe or accessing files that are not in the Web directory. File monitoring may be used to detect changes to files in the Web directory of a Web server that do not match with updates to the Web server’s content and may indicate implantation of a Web shell script. Log authentication attempts to the server and any unusual traffic patterns to or from the server and internal network. Defense Evasion [TA0005] Indicator Removal on Host: Clear Windows Event Logs [T1070.001]

The threat actor created new accounts on victim networks to perform cleanup operations. The accounts created were used to clear the following Windows event logs: System, Security, Terminal Services, Remote Services, and Audit. 

The threat actor also removed applications they installed while they were in the network along with any logs produced. For example, the VPN client installed at one third-party commercial facility was deleted along with the logs that were produced from its use. Finally, data generated by other accounts used on the systems accessed were deleted.

Note: this activity also applies to:

  • Tactic: Persistence [TA0003], Technique: Create Account: Local Account [T1136.001]

Encrypt Sensitive Information: protect sensitive information with strong encryption.

Remote Data Storage: use remote security log and sensitive file storage where access can be controlled better to prevent exposure of intrusion detection log data or sensitive information.

Restrict File and Directory Permissions: restrict access by setting directory and file permissions that are not specific to users or privileged accounts.

Indicator Removal on Host: File Deletion [T1070.004]

The threat actor cleaned up target networks by deleting created screenshots and specific registry keys. 

The threat actor also deleted all batch scripts, output text documents, and any tools they brought into the environment, such as scr.exe.

Note: this activity also applies to:

  • Technique: Modify Registry [T1112]
Monitor: monitoring for command-line deletion functions to correlate with binaries or other files that an adversary may drop and remove may lead to detection of malicious activity. Another good practice is monitoring for known deletion and secure deletion tools that are not already on systems within an enterprise network that an adversary could introduce. Some monitoring tools may collect command-line arguments, but may not capture DEL commands since DEL is a native function within cmd.exe.
  Technique: Masquerading [T1036] After downloading tools from a remote server, the threat actor renamed the extensions.

Restrict File and Directory Permissions: restrict access by setting directory and file permissions that are not specific to users or privileged accounts.

Code Signing: enforce binary and application integrity with digital signature verification to prevent untrusted code from executing.

Execution Prevention: block execution of code on a system through application control, and/or script blocking.

Credential Access [TA0006] Brute Force: Password Cracking [T1110.002]

The threat actor used password-cracking techniques to obtain the plaintext passwords from obtained credential hashes.

The threat actor dropped and executed open-source and free password cracking tools such as Hydra, SecretsDump, and CrackMapExec, and Python.

MFA: enforce use of two or more pieces of evidence (such as username and password plus a token, e.g., a physical smart card or token generator) to authenticate to a system.

Password Policies: set and enforce secure password policies for accounts.

Forced Authentication [T1187] Microsoft Word attachments sent via spearphishing emails leveraged legitimate Microsoft Office functions for retrieving a document from a remote server over Server Message Block (SMB) using Transmission Control Protocol ports 445 or 139. As a part of the standard processes executed by Microsoft Word, this request authenticates the client with the server, sending the user’s credential hash to the remote server before retrieving the requested file. (Note: transfer of credentials can occur even if the file is not retrieved.)

Password Policies: set and enforce secure password policies for accounts.

Filter Network Traffic: use network appliances to filter ingress or egress traffic and perform protocol-based filtering. Configure software on endpoints to filter network traffic.

The threat actor’s watering hole sites contained altered JavaScript and PHP files that requested a file icon using SMB from an IP address controlled by the threat actors.

The threat actor manipulated LNK files to repeatedly gather user credentials. Default Windows functionality enables icons to be loaded from a local or remote Windows repository. The threat actor exploited this built-in Windows functionality by setting the icon path to a remote server controller by the actors. When the user browses to the directory, Windows attempts to load the icon and initiate an SMB authentication session. During this process, the active user’s credentials are passed through the attempted SMB connection.
 

Note: this activity also applies to:

  • Tactic: Persistence [TA0003], Technique: Boot or Logon Autostart Execution: Shortcut Modification [T1547.009]
OS Credential Dumping: Local Security Authority Subsystem Service (LSASS) Memory [T1003.001] The threat actor used an Administrator PowerShell prompt to enable the WDigest authentication protocol to store plaintext passwords in the LSASS memory. With this enabled, credential harvesting tools can dump passwords from this process’s memory.

Operating System Configuration: make configuration changes related to the operating system or a common feature of the operating system that result in system hardening against techniques.

Password Policies: set and enforce secure password policies for accounts.

Privileged Account Management: manage the creation of, modification of, use of, and permissions associated with privileged accounts, including SYSTEM and root.

Privileged Process Integrity: protect processes with high privileges that can be used to interact with critical system components through use of protected process light, anti-process injection defenses, or other process integrity enforcement measures.

User Training: train users to be aware of access or manipulation attempts by an adversary to reduce the risk of successful spearphishing, social engineering, and other techniques that involve user interaction.

Credential Access Protection: use capabilities to prevent successful credential access by adversaries; including blocking forms of credential dumping.

OS Credential Dumping: NTDS [T1003.003] The threat actor collected the files ntds.dit. The file ntds.dit is the Active Directory (AD) database that contains all information related to the AD, including encrypted user passwords.

Monitor: monitor processes and command-line arguments for program execution that may be indicative of credential dumping, especially attempts to access or copy the NTDS.dit.

Privileged Account Management: manage the creation of, modification of, se of, and permissions associated with privileged accounts, including SYSTEM and root.

User Training: train users to be aware of access or manipulation attempts by an adversary to reduce the risk of successful spearphishing, social engineering, and other techniques that involve user interaction.

Discovery [TA0007] Remote System Discovery [T1018]

The threat actor used privileged credentials to access the Energy Sector victim’s domain controller. Once on the domain controller, the threat actors used batch scripts dc.bat and dit.bat to enumerate hosts, users, and additional information about the environment. 

Note: this activity also applies to: 

  • Tactic: Persistence [TA0003], Technique: Valid Accounts: Domain Accounts [T1078.002]
  • Tactic: Discovery [TA0007], Technique: System Owner/User Discovery [T1033]

Monitor: normal, benign system and network events related to legitimate remote system discovery may be uncommon, depending on the environment and how they are used.

Monitor processes and command-line arguments for actions that could be taken to gather system and network information.

Monitor for processes that can be used to discover remote systems, such as ping.exe and tracert.exe, especially when executed in quick succession.

The threat actor accessed workstations and servers on corporate networks that contained data output from control systems within energy generation facilities. The threat actors accessed files pertaining to ICS or supervisory control and data acquisition (SCADA) systems. 

The actor targeted and copied profile and configuration information for accessing ICS systems on the network. The threat actor copied Virtual Network Connection (VNC) profiles that contained configuration information on accessing ICS systems and took screenshots of a Human Machine Interface (HMI).

Note: this activity also applies to

  • Tactic: Discovery [TA0007], Technique File and Directory Discovery [T1083]
  • Tactic: [TA0009], Technique: Screen Capture [T1113]
File and Directory Discovery [T1083]

The actor used dirsb.bat to gather folder and file names from hosts on the network.

Note: this activity also applies to: 

  • Tactic: Execution [TA0002], Command and Scripting Interpreter: Windows Command Shell [T1059.003]
This type of attack technique cannot be easily mitigated with preventive controls since it is based on the abuse of system features. Monitor processes and command-line arguments for actions that could be taken to gather system and network information. Remote access tools with built-in features may interact directly with the Windows API to gather information. The threat actor conducted reconnaissance operations within the network. The threat actor focused on identifying and browsing file servers within the intended victim’s network. Lateral Movement [TA0008] Lateral Tool Transfer [T1570]

The threat actor moved laterally via PsExec, batch scripts, RDP, VNC, and admin shares.

Note: this activity also applies to:

  • Tactic: Lateral Movement [TA0008], Techniques: 
    • Remote Services: Remote Desktop Protocol [T1021.001]
    • Remote Services: SMB/Windows Admin Shares [T1021.002]
    • Remote Services: VNC [T1021.005]

Network Intrusion Prevention: use intrusion detection signatures to block traffic at network boundaries.

Network Segmentation: architect sections of the network to isolate critical systems, functions, or resources. Use physical and logical segmentation to prevent access to potentially sensitive systems and information. Use a DMZ to contain any internet-facing services that should not be exposed from the internal network.

Operating System Configuration: make configuration changes related to the operating system or a common feature of the operating system that result in system hardening against techniques.

Privileged Account Management: manage the creation of, modification of, use of, and permissions associated with privileged accounts, including SYSTEM and root.

User Account Management: manage the creation of, modification o, se of, and permissions associated with user accounts.

Disable or Remove Feature or Program: remove or deny access to unnecessary and potentially vulnerable software to prevent abuse by adversaries.

Audit: audit or scan systems, permissions, insecure software, insecure configurations, etc. to identify potential weaknesses.

MFA: enforce use of two or more pieces of evidence (such as username and password plus a token, e.g., a physical smart card or token generator) to authenticate to a system.

Limit Access to Resource Over Network: prevent access to file shares, remote access to systems, and unnecessary services. Mechanisms to limit access may include use of network concentrators, RDP gateways, etc.

Filter Network Traffic: use network appliances to filter ingress or egress traffic and perform protocol-based filtering. Configure software on endpoints to filter network traffic.

Limit Software Installation: block users or groups from installing unapproved software.

Collection [TA0009] Data from Local System [T1005]  The threat actor collected the Windows SYSTEM registry hive file, which contains host configuration information.

Monitor: monitor processes and command-line arguments for actions that could be taken to collect files from a system. Remote access tools with built-in features may interact directly with the Windows API to gather data.

Data may also be acquired through Windows system management tools such as WMI and PowerShell.

Archive Collected Data: Archive via Utility [T1560.001] The threat actor compressed the ntds.dit file and the SYSTEM registry hive they had collected into archives named SYSTEM.zip and comps.zip. Audit: audit or scan systems, permissions, insecure software, insecure configurations, etc. to identify potential weaknesses. Screen Capture [T1113]

The threat actor used Windows’ Scheduled Tasks and batch scripts, to execute scr.exe and collect additional information from hosts on the network. The tool scr.exe is a screenshot utility that the threat actor used to capture the screen of systems across the network.

Note: this activity also applies to: 

  • Tactic: Execution [TA0002], Techniques: 
    • Command and Scripting Interpreter: Windows Command Shell [T1059.003]
    • Scheduled Task/Job: Scheduled Task [T1053.005]

Network Segmentation: architect sections of the network to isolate critical systems, functions, or resources. Use physical and logical segmentation to prevent access to potentially sensitive systems and information. Use a DMZ to contain any internet-facing services that should not be exposed from the internal network.

MFA: enforce use of two or more pieces of evidence (such as username and password plus a token, e.g., a physical smart card or token generator) to authenticate to a system.

Limit Access to Resource Over Network: prevent access to file shares, remote access to systems, and unnecessary services. Mechanisms to limit access may include use of network concentrators, RDP gateways, etc.

Disable or Remove Feature or Program: remove or deny access to unnecessary and potentially vulnerable software to prevent abuse by adversaries.

The actor used batch scripts labeled pss.bat and psc.bat to run the PsExec tool. PsExec was used to execute scr.exe across the network and to collect screenshots of systems in a text file.

Note: this activity also applies to: 

  • Tactic: Execution [TA0002], Techniques: 
    • Command and Scripting Interpreter: Windows Command Shell [T1059.003]
    • System Services: Service Execution [T1569.002]
Command and Control [TA0011] Ingress Tool Transfer [T1105] The threat actor downloaded tools from a remote server.    

Monitor: monitor for file creation and files transferred into the network. Unusual processes with external network connections creating files on-system may be suspicious. Use of utilities, such as File Transfer Protocol, that does not normally occur may also be suspicious.

Analyze network data for uncommon data flows (e.g., a client sending significantly more data than it receives from a server). Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.

Analyze packet contents to detect communications that do not follow the expected protocol behavior for the port that is being used.

Use intrusion detection signatures to block traffic at network boundaries.

Brought to you by Dr. Ware, Microsoft Office 365 Silver Partner, Charleston SC.