Brute Force I/O
Where this stands
No Sigma rule can address this — the telemetry MITRE names has no Sigma logsource behind it.
Sigma has no logsource taxonomy for ICS. MITRE's telemetry here is operational historians and controller state, which no Sigma rule can address.
What the technique is
Adversaries may repetitively or successively change I/O point values to perform an action. Brute Force I/O may be achieved by changing either a range of I/O point values or a single point value repeatedly to manipulate a process function. The adversary's goal and the information they have about the target environment will influence which of the options they choose. In the case of brute forcing a range of point values, the adversary may be able to achieve an impact without targeting a specific point. In the case where a single point is targeted, the adversary may be able to generate instability on the process function associated with that particular point. Adversaries may use Brute Force I/O to cause failures within various industrial processes. These failures could be the result of wear on equipment or damage to downstream equipment.
Read it on attack.mitre.orgWhat MITRE says you would watch
- AN1870
Monitor operational process data for write commands for an excessive number of I/O points or manipulating a single value an excessive number of times. 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. Some asset application logs may provide information on I/O points related to write commands. Monitor for write commands for an excessive number of I/O points or manipulating a single value an excessive number of times. […]
Technique names and descriptions © MITRE ATT&CK®, CC BY 4.0. Not endorsed by MITRE.