Hey everyone! 👋 I’ve been lurking here for a while, mostly dealing with cloud cost stuff, but my team just rolled out SentinelOne and I’ve been handed the reins for policy tuning. I’ll be honest—the console is a bit overwhelming coming from a more observability/FinOps background.
We’re running a mix of AWS workloads (some EC2, some ECS containers) and a handful of on-prem dev machines. The out-of-the-box policies seem... very aggressive? We’ve already had a few false positives on our CI/CD runners where build scripts got flagged. I’m worried about both security and developer experience.
I know the best practice is to start with a monitoring-only policy, but I’m not sure where to go from there. Should I duplicate the default policy and tweak it per workload type? Or create a brand new one from scratch? Also, any tips on which exclusions are safe to add early on for dev environments without opening up a hole?
If anyone has a sample policy structure or a tuning workflow they’ve had success with, I’d really appreciate it. Especially if you’ve dealt with containerized workloads—I’m curious about how you handle runtime protection there without killing pod startup.
Thanks in advance! This feels as complex as tuning CloudWatch alarms was when I first started, but with higher stakes 😅
cost first, then scale
You're already on the right track by identifying workload types. Duplicating and tweaking the default is the pragmatic starting point. Create separate policy groups: one for your CI/CD runners, one for general AWS EC2, one for ECS containers, and one for on-prem dev boxes. Don't build from scratch.
For your CI/CD false positives, start with path-based exclusions for your build directories and tool caches (like `/opt/buildagent/work/` or wherever your runner unpacks things). Process-based exclusions for your legitimate build tools (like `npm`, `gradle`, `docker build`) are also relatively safe in that controlled environment. The hole you open is small and known.
Containers are a different beast. If you're using the agent inside the container image, you'll need to dial back runtime protection on the startup phase or you'll cause timeouts. Look for the policy settings around script injection and cross-process activity and set those to Monitor for your ECS group initially. Let it run for a week, review the Critical Events log, and only then start blocking the clearly malicious stuff you've observed. It's a grind, not a one-time setup.
Been there, migrated that
Duplicating the default and creating separate policy groups is solid advice. The key for tuning, especially from a monitoring-only baseline, is to treat your exclusions like a change log - document each one with the business justification and a date.
For containers, I'd add a caution on path exclusions: be very specific. Something like `/var/lib/docker/overlay2/*/merged/app` is safer than excluding the entire overlay2 directory. Also, consider whether you're using the agent inside the image or as a sidecar; the runtime protection settings differ significantly.
What's your current logging retention period? You'll want to ensure you keep enough history to validate that an exclusion didn't actually mask a real threat.
Starting with a monitoring-only policy is the right move. Duplicate the default policy for each workload type rather than building from scratch - it's easier to back out changes if needed.
For CI/CD, I'd prioritize process-based exclusions over path exclusions initially. Create an allow list for your build tools (e.g., `java`, `go`, `docker`) specifically in the CI policy. This is generally safer than excluding entire directories where scripts could be dynamically created.
On containers, the biggest tuning mistake I see is applying the same runtime protection thresholds to containerized workloads as to regular servers. For ECS, dial back the "script execution" and "suspicious process" protections substantially - containers legitimately spin up many short-lived processes that look anomalous. Start with thresholds at 50-60% of your server policy values, then adjust based on alerts.
What's your alert volume looking like right now in monitoring mode?
BenchMark
Good advice here already. I'd start by cloning the default policy for just your CI/CD runners first, since that's where you're seeing immediate noise. Flip that one to monitor-only and see what else pops up for a day or two before you even add exclusions. That'll give you a better baseline.
On the container side, we had the same worry about pod startup. We found lowering the "script execution" threshold in the runtime protection settings made a huge difference for our ECS tasks. The defaults are really meant for long-lived servers.
What's your plan for tracking the changes you make? I'm using a simple spreadsheet linked to our ticketing system for now, but it's a bit clunky.