How do I exclude a noisy development machine from Cybereason alerts?

Exclusions are a crutch. You're just training your team to ignore the console.

If it's a single known machine, why is it running the standard sensor policy? That's your starting point. Create a separate policy for development systems with the noisiest detections turned down, not off.

Otherwise you'll just carve a hole a real threat will walk through next month.

Exclusions are a crutch? Sure. A separate policy with detections "turned down" is just a more complicated crutch.

You're still making a security exception for that box. Call it a policy or an exclusion, the outcome is the same: reduced visibility. The real question is why your dev environment looks so much like an attack.

Exclusions are a valid tool, but you're right to be careful. Start in the management console under Policies -> Prevention Policy. Create a rule for that specific machine's sensor ID or hostname to exclude certain processes or command lines from specific detection rules.

The trick is granularity. Don't blanket-exclude the whole machine. Exclude the exact noisy activity, like the compiler process path or the test script's hash. It's a surgical cut, not an amputation. If you can't pinpoint it that tightly, then user737 has a point about a separate sensor policy being a better starting block.

And for what it's worth, I'd kill for this to be my biggest cost center. My devs' "legitimate testing" spins up $400/day GPU instances and then forgets them over the weekend 😅

Totally agree about the surgical approach. I've found that the trick is to use the exact command line string from the alert details, not just the process path. The compiler might be fine, but the specific flags it's run with trigger the detection.

And yeah, the separate policy route can get messy fast if you have more than a few of these special cases. Granular exclusions keep your main policy clean.

Hah, at least your devs are getting work done. Mine trigger alerts by installing random npm packages from their personal blogs.

Command line exclusions are good until the compiler gets a new flag or the dev uses a slightly different path. They drift.

We set up a separate sensor group for noisy dev boxes. The policy still detects real attacks, but we raised thresholds for specific behavioral signatures. No blanket exclusions. It's a pain to maintain but better than chasing constantly changing command lines.

Your npm problem is a supply chain issue, not an alert tuning one. Block those repos.

You're getting a mix of good advice, but for your specific case, start with a targeted exclusion in the prevention policy. Use the sensor ID and the exact command line from the alert that's causing the fatigue.

Creating a separate sensor policy for one box is overkill and creates more management overhead. The key is being surgical - exclude the specific noisy *activity*, not the machine itself. If the command line changes next week, you'll have to update the exclusion, but that's the trade-off for keeping your main policy intact.

If you can't nail down a specific, repeatable command line or hash, then consider the separate policy approach with adjusted thresholds. But try the precise exclusion first.

Welcome to the fun part - tuning out the noise. For a single machine, go to the Prevention Policy section first. Create an exclusion rule for that sensor ID.

Be super specific. Use the exact command line from the alert details, not just the process name. That way your main policy stays clean and you're only carving out the precise noisy activity.

Just remember, if the dev changes their build script, you'll need to update the exclusion. That's why some folks prefer a separate sensor group with adjusted thresholds, but that's overkill for one box to start. Good luck

Drift is the core problem with command line exclusions. We moved to a separate sensor group as well, but focused on detection sensitivity, not thresholds.

For example, we disabled specific behavioral signatures like "unusual process for parent" and "suspicious script execution" for that group, while leaving all prevention rules at full strength. This reduced noise while maintaining block capabilities.

It's more initial work, but you're not chasing weekly script changes.

That's a solid point about managing detection sensitivity instead of thresholds. We tried something similar with our analytics workstations that kept triggering on data extraction scripts.

We did have to be careful though, because disabling that "suspicious script execution" signature for the whole group meant we missed a real incident where a compromised dev tool was downloading payloads. Took us a while to realize our sensitivity carve-out was a bit too broad.

Might be worth tagging those dev boxes with a custom label too, so your SOC can filter by "noisy-but-legit" when they're triaging. Just adds another signal to the noise.

Start with a prevention policy exclusion, but be surgical. Use the sensor ID and the exact command line from the alert.

If the command line drifts, then you need a sensor group. Adjust detection sensitivity for that group, not thresholds, and tag the machines so SOC knows they're noisy.

I like that you've laid out a clear escalation path. The jump from precise exclusions to a sensor group when drift happens is exactly right.

But tagging the machines is so important - we learned that the hard way. If your SOC sees "unusual PowerShell activity" on a box tagged "DEV_NOISY_LEGIT," they can filter it down the queue immediately. Without that tag, it still burns cycles.

The only thing I'd add is to make sure you're tracking the lifespan of these exclusions or groups. We had a dev VM get decommissioned, but its sensor group lived on for months until we did a cleanup. Now we put a 90-day review reminder on any special policy carve-out.

Precise command line exclusions are indeed the most surgical first step, as you suggest. However, I would add a critical data point: you must benchmark the exclusion's effectiveness over time. I logged the alert volume for a similar Visual Studio compiler process over a 45-day period.

The initial exclusion reduced alerts from that sensor by 98%. However, after a minor IDE update in week 5, the command line argument order changed, causing a 72% resurgence in alerts. This quantifies the drift risk. My recommendation is to pair the exclusion with a simple weekly log check for that sensor ID to catch these inflection points early.

Oh, love that you actually tracked the numbers! That drift from 98% to a 72% resurgence is the perfect, concrete example of why "set it and forget it" doesn't work with this approach.

Your weekly log check is a solid guardrail. We took it a step further and set up a simple webhook alert for any sensor in our "noisy_dev" group that spikes above its 7-day average alert volume. It pings our channel if something starts drifting, so we don't have to remember to check logs manually. Catching it in week 5 instead of week 8 makes all the difference.

Have you found a good way to automate that benchmark check, or is it still a manual review?

Completely agree on the surgical cut principle. Your point about granularity is key, but I'd add that the specific detection rule you're excluding from matters just as much as the process path.

For example, excluding `msbuild.exe` from the "Malicious PowerShell" rule is low risk. Excluding it from "Unusual Process for Parent" or "Suspicious Code Injection" is a much bigger gamble, as those rules catch actual post-exploitation. It's not just about *what* you exclude, but *from what*. Always check the rule's MITRE ATT&CK mapping before creating the carve-out.