Industrial Cybersecurity & OT Risk worked example

USB Control Risk Reduction with impact of removable-media compromise of 3.5 score: a worked example

This worked example runs the usb control risk reduction numbers for a tougher week than the baseline: impact of removable-media compromise of 3.5 score instead of the typical 7 score. Score risk reduction from USB control improvements using removable media impact, exposure, and control weakness.

The inputs for this scenario

  • Impact of removable-media compromise: 3.5 score (the input this scenario stresses; the baseline uses 7)
  • Likelihood of removable-media exposure: 6 score (held at the documented default)
  • USB control gap (weakness of safeguards): 5 score (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: USB control risk score = removable media impact score × removable media exposure score × USB control weakness score.
  • USB control risk score works out to 4.75 score at these inputs, and this is the headline figure for the scenario.
  • Removable media impact score works out to 3.5 score at these inputs.
  • Removable media exposure score works out to 6 score at these inputs.
  • USB control weakness score works out to 5 score at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where impact of removable-media compromise sits at 7 score and the headline result is 6.15 score, this scenario comes in 22.76% below the baseline at 4.75 score.
  • Use it before and after deploying USB controls - port locks, scanning kiosks, device whitelisting - to quantify the risk reduction each measure delivers. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • USB control risk score: 4.75 score (headline result)
  • Removable media impact score: 3.5 score
  • Removable media exposure score: 6 score
  • USB control weakness score: 5 score

Run it with your numbers

  • To rerun this with your own numbers, open the live USB Control Risk Reduction calculator, set impact of removable-media compromise to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.