A threat actor who has already authenticated with a stolen credential does not look like an intruder to most detection systems. They look like a user. By the time your SIEM generates an alert, the session may be hours old.
TacitRed approaches this problem from the outside in. Instead of waiting for an internal signal to fire, it monitors external-facing risk before an attacker ever touches your environment.
What the Platform Actually Monitors
TacitRed watches four categories of external identity risk:
- Compromised credentials: username and password pairs that have appeared in breach dumps, stealer logs, or dark-web markets
- Leaked secrets: API keys, tokens, and service account credentials exposed in public repositories or paste sites
- Dark-web exposure: mentions of your organization, domains, or users in forums and marketplaces where access is sold
- Anomalous external connections: outbound connections from your network to known-malicious infrastructure, detected through internet-scale NetFlow telemetry
The NetFlow signal is the part most teams do not have elsewhere. TacitRed consumes telemetry at internet scale to identify when a host inside your perimeter has communicated with infrastructure that is already flagged as malicious. That connection may not have triggered a firewall block or a SIEM rule, but it still appears in the NetFlow record. TacitRed surfaces it.
A Concrete Scenario
Suppose a developer’s laptop is infected with an infostealer. The stealer exfiltrates credentials, which appear in a criminal marketplace within 24 to 48 hours. Simultaneously, the laptop begins making periodic callback connections to a command-and-control host.
Without external telemetry, your internal controls see nothing unusual. The developer’s Active Directory account is still valid. No authentication anomaly has fired. The C2 callbacks may be low-volume enough to avoid signature detection.
TacitRed catches this at two points. First, it flags the credential pair when it appears externally, before anyone uses it to authenticate. Second, it flags the anomalous outbound NetFlow connection to the C2 host, independently of whether any endpoint agent detected the malware.
The result is two separate signals, each actionable on its own, both pointing at the same affected user.
How Signals Move into Enforcement
Detection that stays in one console has limited value. TacitRed ships as a Microsoft Sentinel solution, which means indicators flow directly into Sentinel’s analytics pipeline where you can correlate them against your existing detection rules, hunting queries, and workbooks.
For enforcement rather than alerting, TacitRed pushes high-confidence indicators into CrowdStrike Falcon and SentinelOne automatically. A compromised credential flagged externally can trigger an account isolation or policy action in Falcon or SentinelOne without requiring an analyst to move between platforms and make a manual call.
This matters because identity risk has a short window. A credential that appears on a dark-web market may be tested against your environment within hours. If the signal has to travel through a ticket queue before anyone acts, that window closes.
What "High-Confidence" Means in Practice
Not every indicator in a threat feed deserves automated enforcement. Acting on low-confidence data creates noise and disrupts legitimate users. TacitRed routes high-confidence indicators to enforcement and surfaces lower-confidence signals for investigation rather than automatic response.
The distinction depends on corroboration. A credential appearing in a single low-reputation paste site is a weak signal. The same credential appearing in a structured stealer log alongside device fingerprints and browser cookies is a stronger one. NetFlow connections to infrastructure with no legitimate business relationship, confirmed against multiple telemetry sources, warrant enforcement. TacitRed makes that distinction before it pushes to CrowdStrike or SentinelOne, which keeps false-positive enforcement low.
Where to Look First
If you want to evaluate how much external identity risk your environment is carrying right now, start with these checks:
- Pull your current list of service account credentials and cross-reference against recent stealer log exposure. Service accounts rarely get reset after a breach.
- Review whether any user accounts active in your directory appear in breach data from the last 90 days. Credential stuffing attacks target exactly these accounts.
- Check whether your current SIEM visibility includes outbound NetFlow to threat-intelligence-tagged destinations, or whether that gap exists.
- Confirm whether your CrowdStrike or SentinelOne deployment is configured to accept external threat intelligence indicators for automated response, since the integration is available but not always enabled by default.
TacitRed covers the external monitoring side of this. The internal response side depends on whether your enforcement tools are configured to act on that signal when it arrives.