BAS does not replace pentesting or red team. Pentesting goes deep into applications, business logic and creative paths; red team emulates a full adversary over weeks with contractual objectives. BAS covers defensive coverage at scale and continuously. The three complement each other.
What BAS is
BAS (Breach and Attack Simulation) is the category of platforms that emulates real attack techniques in a controlled, continuous way to validate whether deployed defences work as expected. Unlike a traditional pentest — performed by a human team within a defined window — BAS automates the execution of hundreds or thousands of tests, repeats them at the cadence the organisation decides and measures whether the controls (EDR, SIEM, network segmentation, email, browser) detect or block each technique. Tests are usually mapped to MITRE ATT&CK, which lets you translate control coverage into specific tactics and techniques rather than an empty percentage.
Why it matters
A security committee never asks "how many products do we have deployed?" — it asks "does what we have actually work against the attacks we really receive?". Answers based on acquisition metrics (patches up to date, agents deployed, rules enabled) stop being useful once leadership understands that a deployed agent that does not alert is exactly the same as having no agent. BAS answers that question with evidence: every simulated technique produces a trace that says whether it was detected, blocked or ignored. For programmes aligned with NIS2, DORA or ISO 27001, that continuous evidence is one of the best inputs to demonstrate mature control management.
Key points
The most useful tests are mapped to MITRE ATT&CK by tactic and technique. That lets you produce coverage heatmaps ('we have no detection in execution, persistence and exfiltration') that guide investment clearly.
BAS works well when run as a validation programme, not as a one-off shot. The recommended cadence is weekly or bi-weekly for critical techniques and monthly for the rest. Results are compared over time to detect regressions after version or policy changes.
Integration with the SIEM and the SOC is key. BAS tests must be tagged as such to avoid contaminating incident response, but they must also generate the same kind of telemetry as a real attack to validate rules and playbooks.
A well-governed BAS platform has explicit authority to run its tests and operates in agreed windows. Without clear rules of engagement and IT coordination, the tool ends up being blocked by the defensive team itself or generating false incidents over weekends.
BAS is especially useful after a change: EDR version update, new email policy, new SIEM rule deployment. Repeating the relevant test set confirms that the change did not break detection that already worked.
Example: continuous BAS programme in a company with an in-house SOC
A company with an internal SOC, EDR deployed on the endpoint and cloud email rolls out a BAS platform on a representative subset of equipment. The first full sweep runs 350 MITRE ATT&CK techniques in three hours and returns a coverage map: the EDR detects 92 per cent of execution techniques, 78 per cent of persistence, 64 per cent of lateral movement and only 41 per cent of exfiltration. The company also discovers that the SIEM rules trigger alerts in four out of six use cases considered critical, which suggests tuning two rules and creating a new one.
From that baseline, the team schedules a bi-weekly pass of the critical subset and a monthly full pass, both inside windows agreed with IT. Every major EDR update or policy change triggers an extra comparison pass. Three months later, average coverage has risen to 86 per cent and, more importantly, the team has an honest, comparable view of its offensive-defensive posture that works for the committee and feeds the next threat hunting exercise.
Common mistakes
- Treating BAS as a vulnerability scanner. They solve different problems. A scanner looks for weaknesses per asset; BAS validates whether defences detect or block attack techniques. The two disciplines complement each other but do not replace each other.
- Running BAS without coordinating with IT and the SOC. Tests generate telemetry that looks like real attack; without coordination, the defensive team spends hours on incidents that do not exist and the tool ends up disabled.
- Stopping after the first sweep. BAS value lies in time comparison and regression detection after changes. A one-off run works as an initial diagnosis but does not turn BAS into a programme.
- Confusing coverage with security. A green MITRE ATT&CK heatmap does not mean the organisation is protected: it means the specific techniques simulated were detected. Combined with manual validation by an offensive team, it gives a more faithful picture.
- Replacing red team with BAS. BAS automates many techniques but does not improvise, does not chain, does not exploit human error. An organisation that relies only on BAS loses the real adversarial dimension a red team exercise does offer.
Related terms
Related services
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Frequently asked questions
How does BAS differ from a traditional pentest?
A pentest is performed by a human team in a defined window and goes deep into applications, business logic and creative paths. BAS automates the execution of a broad catalogue of techniques mapped to MITRE ATT&CK and repeats them at the cadence the organisation chooses, measuring whether defences detect or block each one. Pentest delivers depth over a defined scope; BAS delivers continuous coverage. They are complementary disciplines.
Does BAS replace red team exercises?
No. A red team emulates a complete adversary over weeks with contractual objectives and exploits human error, chaining of techniques and opportunities no automated catalogue covers. BAS provides volume, cadence and metrics; red team provides real adversarial pressure. A mature programme combines both.
What technical requirements does deploying BAS have?
Most platforms require lightweight agents on a representative subset of endpoints and servers, an explicit agreement with IT on execution windows and rules of engagement, and integration with SIEM and EDR so the tests are distinguishable from real attacks. Deployment is straightforward; the challenge is governance, not technology.
How is the value of a BAS programme measured?
The most useful metrics are coverage by MITRE ATT&CK tactic (percentage of techniques detected or blocked by category), mean time to detect critical techniques, number of regressions detected after changes, and evolution of the heatmap between runs. These metrics are understood in the committee and guide investment without needing technical detail.