The U.S. military's cybersecurity capabilities aren't advancing fast enough to stay ahead of the "onslaught of multipronged" attacks envisioned by adversaries, the Pentagon's combat testing office is warning.

Despite some progress in fending off attacks staged by in-house "Red Teams," the testing office said, "We estimate that the rate of these improvements is not outpacing the growing capabilities of potential adversaries who continue to find new vulnerabilities and techniques to counter fixes."

Automation and artificial intelligence are beginning to "make profound changes to the cyber domain," a threat that the military hasn't yet fully grasped how to counter, Robert Behler, the Defense Department's director of operational test and evaluation, said in his annual assessment of cyber threats, which was obtained by Bloomberg News.

The test office's findings may be discussed on Tuesday during a Senate Armed Services hearing focused on Pentagon cyber policy with Chief Information Officer Dana Deasy.

The evaluation, part of the testing office's annual report that may be released as early as this week, comes amid other critical appraisals of the military's ability to maintain and improves its defense against computer attacks.

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