Detections

Monitor asset alarms which may help identify a loss of communications. Consider correlating alarms with other data sources that indicate traffic has been blocked, such as network traffic. In cases where alternative methods of communicating with outstations exist alarms may still be visible even if reporting messages are blocked. Monitor for the termination of processes or services associated with ICS automation protocols and application software which could help detect blocked communications. Monitor application logs for changes to settings and other events associated with network protocols that may be used to block communications. Monitor for a loss of network communications, which may indicate this technique is being used. Monitor for lack of operational process data which may help identify a loss of communications. This will not directly detect the technique’s execution, but instead may provide additional evidence that the technique has been used and may complement other detections.

Monitor for firmware changes which may be observable via operational alarms from devices. Monitor device application logs for firmware changes, although not all devices will produce such logs. Monitor ICS management protocols / file transfer protocols for protocol functions related to firmware changes. Monitor firmware for unexpected changes. Asset management systems should be consulted to understand known-good firmware versions. Dump and inspect BIOS images on vulnerable systems and compare against known good images.[1] Analyze differences to determine if malicious changes have occurred. Log attempts to read/write to BIOS and compare against known patching behavior. Likewise, EFI modules can be collected and compared against a known-clean list of EFI executable binaries to detect potentially malicious modules. The CHIPSEC framework can be used for analysis to determine if firmware modifications have been performed.[2][3][4]

Monitor for newly executed processes that depend on user interaction, especially for applications that can embed programmatic capabilities (e.g., Microsoft Office products with scripts, installers, zip files). This includes compression applications, such as those for zip files, that can be used to Deobfuscate/Decode Files or Information in payloads. For added context on adversary procedures and background see User Execution and applicable sub-techniques. Monitor for application logging, messaging, and/or other artifacts that may rely upon specific actions by a user in order to gain execution. Monitor for newly constructed web-based network connections that are sent to malicious or suspicious destinations (e.g., destinations attributed to phishing campaigns). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments (e.g., monitor anomalies in use of files that do not normally initiate network connections or unusual connections initiated by regsvr32.exe, rundll.exe, SCF, HTA, MSI, DLLs, or msiexec.exe). Anti-virus can potentially detect malicious documents and files that are downloaded and executed on the user's computer. Endpoint sensing or network sensing can potentially detect malicious events once the file is opened (such as a Microsoft Word document or PDF reaching out to the internet or spawning PowerShell). Monitor for newly executed processes that depend on user interaction, especially for applications that can embed programmatic capabilities (e.g., Microsoft Office products with scripts, installers, zip files). This includes compression applications, such as those for zip files, that can be used to Deobfuscate/Decode Files or Information in payloads. Monitor and analyze traffic patterns and packet inspection associated with web-based network connections that are sent to malicious or suspicious destinations (e.g., destinations attributed to phishing campaigns). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments (e.g., monitor anomalies in use of files that do not normally initiate network connections or unusual connections initiated by regsvr32.exe, rundll.exe, SCF, HTA, MSI, DLLs, or msiexec.exe).

Consult asset management systems which may help with the detection of computer systems or network devices that should not exist on a network. Monitor for network traffic originating from unknown/unexpected devices or addresses. Local network traffic metadata could be used to identify unexpected connections, including unknown/unexpected source MAC addresses connecting to ports associated with operational protocols. Also, network management protocols such as DHCP and ARP may be helpful in identifying unexpected devices. Monitor for new master devices communicating with outstations, which may be visible in alarms within the ICS environment. Monitor for unexpected ICS protocol functions from new and existing devices. Monitoring known devices requires ICS function level insight to determine if an unauthorized device is issuing commands (e.g., a historian). Monitor for new master devices communicating with outstation assets, which may be visible in asset application logs.

Monitor for any suspicious attempts to enable script execution on a system. If scripts are not commonly used on a system, but enabled, scripts running out of cycle from patching or other administrator functions are suspicious. Scripts should be captured from the file system when possible to determine their actions and intent. Monitor executed commands and associated arguments for application programs which support executing custom code, scripts, commands, or executables. Monitor for unusual processes execution, especially for processes that allow the proxy execution of malicious files.

Monitor industrial process history data for events that correspond with command message functions, such as setpoint modification or changes to system status for key devices. This will not directly detect the technique’s execution, but instead may provide additional evidence that the technique has been used and may complement other detections. Monitor for anomalous or unexpected commands that may result in changes to the process operation (e.g., discrete write, logic and device configuration, mode changes) observable via asset application logs. Monitor for new or unexpected connections to controllers, which could indicate an Unauthorized Command Message being sent via Rogue Master. Monitor for anomalous or unexpected commands that may result in changes to the process operation (e.g., discrete write, logic and device configuration, mode changes) observable via asset application logs. Monitor for unexpected ICS protocol command functions to controllers from existing master devices (including from new processes) or from new devices. The latter is like detection for Rogue Master but requires ICS function level insight to determine if an unauthorized device is issuing commands (e.g., a historian).

Monitoring for unexpected or problematic values below the function level will provide better insights into potentially malicious activity but at the cost of additional false positives depending on the underlying operational process.

Detecting software exploitation may be difficult depending on the tools available. Software exploits may not always succeed or may cause the exploited process to become unstable or crash.

Monitor logon activity for unexpected or unusual access to devices from the Internet. Monitor for unexpected protocols to/from the Internet. While network traffic content and logon session metadata may directly identify a login event, new Internet-based network flows may also be a reliable indicator of this technique. Monitor for unusual logins to Internet connected devices or unexpected protocols to/from the Internet. Network traffic content will provide valuable context and details about the content of network flows.

Monitor asset alarms which may help identify a loss of communications. Consider correlating alarms with other data sources that indicate traffic has been blocked, such as network traffic. In cases where alternative methods of communicating with outstations exist alarms may still be visible even if messages over serial COM ports are blocked. Monitor for a loss of network communications, which may indicate this technique is being used. Monitor for lack of operational process data which may help identify a loss of communications. This will not directly detect the technique’s execution, but instead may provide additional evidence that the technique has been used and may complement other detections. Monitor application logs for changes to settings and other events associated with network protocols that may be used to block communications. Monitor for the termination of processes or services associated with ICS automation protocols and application software which could help detect blocked communications.

Monitor network traffic for hardcoded credential use in protocols that allow unencrypted authentication. Monitor logon sessions for hardcoded credential use, when feasible.

Monitor and analyze traffic flows that do not follow the expected protocol standards and traffic flows (e.g., extraneous packets that do not belong to established flows , or gratuitous or anomalous traffic patterns). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g., monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)). Monitor and analyze traffic patterns and packet inspection associated to protocol(s), leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows (e.g., extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g., monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).

Monitor for newly executed processes that can aid in sniffing network traffic to capture information about an environment. Monitor executed commands and arguments for actions that aid in sniffing network traffic to capture information about an environment.

Monitor for a loss of network communications, which may indicate a device has been shutdown or restarted. This will not directly detect the technique’s execution, but instead may provide additional evidence that the technique has been used and may complement other detections. Device restarts and shutdowns may be observable in device application logs. Monitor for unexpected device restarts or shutdowns. Devices may produce alarms about restarts or shutdowns. Monitor for unexpected device restarts or shutdowns. Monitor ICS automation protocols for functions that restart or shutdown a device. Commands to restart or shutdown devices may also be observable in traditional IT management protocols.

Monitor ICS automation network protocols for information that an asset has been placed into Firmware Update Mode. Monitor device alarms that indicate the devices has been placed into Firmware Update Mode, although not all devices produce such alarms. Monitor asset log which may provide information that an asset has been placed into Firmware Update Mode. Some assets may log firmware updates themselves without logging that the device has been placed into update mode.

Monitor for network traffic originating from unknown/unexpected systems. Monitor authentication logs and analyze for unusual access patterns, windows of activity, and access outside of normal business hours, including use of Valid Accounts. When authentication is not required to access an exposed remote service, monitor for follow-on activities such as anomalous external use of the exposed API or application.

Monitor network data for uncommon data flows (e.g., time of day, unusual source/destination address) that may be related to abuse of Valid Accounts to log into a service specifically designed to accept remote connections, such as RDP, Telnet, SSH, and VNC. Monitor DLL file events, specifically creation of these files as well as the loading of DLLs into processes specifically designed to accept remote connections, such as RDP, Telnet, SSH, and VNC. Monitor for user accounts logged into systems they would not normally access or abnormal access patterns, such as multiple systems over a relatively short period of time. Correlate use of login activity related to remote services with unusual behavior or other malicious or suspicious activity. Adversaries will likely need to learn about an environment and the relationships between systems through Discovery techniques prior to attempting Lateral Movement. For added context on adversary procedures and background see Remote Services and applicable sub-techniques. Monitor for newly executed processes related to services specifically designed to accept remote connections, such as RDP, Telnet, SSH, and VNC. The adversary may use Valid Accounts to login and may perform follow-on actions that spawn additional processes as the user. Monitor executed commands and arguments to services specifically designed to accept remote connections, such as RDP, Telnet, SSH, and VNC. The adversary may then perform these actions using Valid Accounts. Monitor for newly constructed network connections into a service specifically designed to accept remote connections, such as RDP, Telnet, SSH, and VNC. Monitor network connections involving common remote management protocols, such as ports tcp:3283 and tcp:5900, as well as ports tcp:3389 and tcp:22 for remote logins. The adversary may use Valid Accounts to enable remote logins. Monitor interactions with network shares, such as reads or file transfers, using remote services such as Server Message Block (SMB). For added context on adversary procedures and background see Remote Services and applicable sub-techniques.

Much of this activity may have a very high occurrence and associated false positive rate, as well as potentially taking place outside the visibility of the target organization, making detection difficult for defenders.

Detection efforts may be focused on related stages of the adversary lifecycle, such as during Initial Access.

Much of this activity may have a very high occurrence and associated false positive rate, as well as potentially taking place outside the visibility of the target organization, making detection difficult for defenders.

Detection efforts may be focused on related stages of the adversary lifecycle, such as during Initial Access.

Much of this activity may have a very high occurrence and associated false positive rate, as well as potentially taking place outside the visibility of the target organization, making detection difficult for defenders.

Detection efforts may be focused on related stages of the adversary lifecycle, such as during Initial Access.

Much of this activity will take place outside the visibility of the target organization, making detection of this behavior difficult. Detection efforts may be focused on behaviors relating to the potential use of exploits for vulnerabilities (i.e. Exploit Public-Facing Application, Exploitation for Client Execution, Exploitation for Privilege Escalation, Exploitation for Stealth, Exploitation for Credential Access, Exploitation of Remote Services, and Application or System Exploitation).

Much of this activity may have a very high occurrence and associated false positive rate, as well as potentially taking place outside the visibility of the target organization, making detection difficult for defenders.

Detection efforts may be focused on related stages of the adversary lifecycle, such as during Initial Access.

Monitor for suspicious network traffic that could be indicative of adversary reconnaissance, such as rapid successions of requests indicative of web crawling and/or large quantities of requests originating from a single source (especially if the source is known to be associated with an adversary). Analyzing web metadata may also reveal artifacts that can be attributed to potentially malicious activity, such as referer or user-agent string HTTP/S fields.

Much of this activity may have a very high occurrence and associated false positive rate, as well as potentially taking place outside the visibility of the target organization, making detection difficult for defenders.

Detection efforts may be focused on related stages of the adversary lifecycle, such as during Initial Access.

Much of this activity may have a very high occurrence and associated false positive rate, as well as potentially taking place outside the visibility of the target organization, making detection difficult for defenders.

Detection efforts may be focused on related stages of the adversary lifecycle, such as during Initial Access.

Much of this activity may have a very high occurrence and associated false positive rate, as well as potentially taking place outside the visibility of the target organization, making detection difficult for defenders.

Detection efforts may be focused on related stages of the adversary lifecycle, such as during Initial Access.