Breach and Attack Simulation (BAS) vs Penetration Testing: What Each One Proves

Breach and attack simulation (BAS) is software that runs a library of safe, scripted attack techniques against your own security controls, on a schedule, and reports which ones your email filter, endpoint protection, web proxy and SIEM blocked, alerted on, or missed. A penetration test is an engagement in which a skilled person finds weaknesses in a defined scope, exploits them, and proves how far an attacker could get. BAS asks “do our defenses still work against the techniques we know about?” A penetration test asks “how would someone actually get in, and what could they reach?” A mature program usually runs both, and neither stands in for the other in an audit.

We sell the human side of this: penetration tests and red teams with starting prices on our pricing page, plus purple team assessments and PTaaS programs, which are scoped and quoted. We do not sell BAS software, so read this as a buyer’s guide from a firm with a point of view, including the cases where BAS is the better next purchase.

Breach and attack simulation vs penetration testing at a glance

	Breach and attack simulation	Penetration test
Question it answers	Do our controls block or detect known techniques today?	How would an attacker get in, and how far would they get?
What it exercises	Your defenses: EDR, email and web gateways, firewall, DLP, SIEM rules	Your attack surface: hosts, identities, applications, cloud
Who runs it	Usually your own team, on a vendor platform	A qualified tester independent of the systems
How often	Daily, weekly, or after every change	At least annually, and after significant change
Finds new vulnerabilities	Rarely; it assumes the attacker’s step and checks the control	Yes, that is the point
Business logic and chained attack paths	Only what a scenario scripts	Yes, including paths unique to your environment
Measures detection and alerting	Yes, technique by technique	Only when scoped for it (red and purple teams are)
Counts as the PCI DSS or NYDFS penetration test	No	Yes, when scoped to the requirement

How breach and attack simulation works

A BAS platform has three parts. Agents sit on endpoints, servers and network segments. A content library holds attack scenarios mapped to MITRE ATT&CK, whose current release, v20 from October 2026, lists 227 enterprise techniques and 479 sub-techniques. A console schedules runs and checks your EDR and SIEM, usually through their APIs, to see whether an alert fired.

Scenarios come in a few families. Endpoint scenarios reproduce a technique’s behavior on an agent with harmless stand-ins, such as a process opening credential memory. Network scenarios send lateral movement, command-and-control or exfiltration traffic between agents or out to the internet. Email and web scenarios deliver malicious-looking attachments to a monitored mailbox or request known-bad URLs through the proxy. Kill-chain scenarios string the steps together to emulate a named ransomware family. Each technique ends as blocked, detected, logged but not alerted, or missed.

Vendors selling under the BAS label include AttackIQ, Cymulate, Picus Security and SafeBreach. Open-source options include Apache Caldera (incubating), an automated adversary emulation platform that MITRE built and contributed to the Apache Software Foundation in 2026, and Atomic Red Team, a library of small tests mapped to ATT&CK. Our guide to red team tools covers both.

Gartner now groups BAS with automated penetration testing and red teaming tools under adversarial exposure validation: technology that gives continuous, automated evidence of whether an attack is feasible. It serves the validation stage of a CTEM program. The mechanics still differ. BAS replays known techniques against your controls; an autonomous pentest platform tries to exploit real weaknesses and pivot. Our guide to autonomous penetration testing vendors and our Invadel vs Pentera comparison cover the second group.

Security validation: what BAS automates

Security validation, also called security control validation, is what BAS automates: proving a control does what you bought it to do, rather than trusting that it is installed. Government guidance now asks for it directly. CISA’s SafePay advisory of October 20, 2026, like other recent #StopRansomware advisories, ends with six steps: pick an ATT&CK technique from the advisory, align your security technologies against it, test them, analyze detection and prevention performance, repeat for every technology, and tune people, process and technology on the results. It recommends “continually testing your security program, at scale, in a production environment.”

That is a BAS workflow, and the control catalogs keep it separate from penetration testing. NIST SP 800-53 Rev. 5 has SI-4(9), an enhancement for testing intrusion-monitoring tools at a frequency the organization defines. Penetration testing is a different control, CA-8, whose guidance says it goes beyond automated scanning and is done by people with demonstrable skill and experience; CA-8(1) adds an independent tester. BAS is good evidence for the first and is not the second.

What a penetration test finds that BAS cannot

A penetration test starts from your environment, not a library. New York’s financial regulator defines it as testing security by attempting to circumvent or defeat an information system’s security features (23 NYCRR 500.1(l)). What testers commonly find that a BAS library has no scenario for:

• The way in. An unpatched VPN appliance, a forgotten staging server, an account without MFA. Most BAS scenarios assume the foothold.
• Environment-specific attack paths. A weak service account password, a certificate template any user can abuse, a share holding a script with credentials. Minor alone; chained, they reach Domain Admin. Finding that chain is the job of an internal network penetration test.
• Application flaws. One customer reading another’s invoice by changing an ID. No ATT&CK technique describes your product’s access model.
• Hosts the agents never see. Unmanaged servers, printers and contractor laptops are where testers often land.

Our guide to automated vs manual penetration testing covers the wider split.

Where BAS earns its place

• Control drift. An EDR policy loosened for a ticket and never restored, an agent that stops reporting, a SIEM rule broken by a log format change. BAS catches it within days; an annual test, once a year at best.
• New threats, fast. When an advisory lands, run its techniques against your stack that week.
• Detection, not just prevention. A pentest proves an attacker could dump credentials. BAS tells you weekly whether your SOC would have known.
• Trend data you can report to the board, and fair side-by-side comparisons of tools before a renewal.

The catch: BAS produces work, not fixes. Every missed technique is a ticket for a detection engineer, and teams without one end up with a dashboard of red. The real prerequisite is people, not budget. Managed BAS services exist for teams without that capacity.

When you shortlist platforms, ask each vendor:

• How quickly do new advisory techniques reach the library?
• Which EDR and SIEM integrations score detections automatically?
• Which scenarios are approved for production?
• How does pricing scale with agents and modules?
• Does it cover cloud and identity?

BAS, automated pentesting, red teams and purple teams

Approach	Driven by	Main question	Cadence
Vulnerability scanning	Software	Which known vulnerabilities are present?	Weekly to monthly
Breach and attack simulation	Software, run by your team	Do our controls catch known techniques?	Continuous
Autonomous penetration testing	Software, run by your team	Which exposures can be exploited and chained?	Monthly or on demand
Manual penetration test	Skilled testers	How would an attacker get in, and how far?	Annually and after major change
Red team	Covert operators	Would we detect and stop a determined attacker?	Annually, once detection is mature
Purple team	Operators with your defenders	How do we make sure each technique is detected?	After a red team, or quarterly

A purple team is the closest human equivalent of BAS: operators run techniques in the open while your defenders watch what fires, tune, and re-run. BAS then keeps those gains from eroding. Our guide to red team vs blue team explains how the roles fit, and our list of red team companies helps you compare providers.

Reading BAS results: from technique to telemetry

When a technique comes back missed, look here. Several of these logs are off by default, a common cause of misses.

ATT&CK technique	What the scenario simulates	Control that should respond	Telemetry to check
T1566.001 Spearphishing Attachment	Malicious-looking attachment to a monitored mailbox	Email gateway, sandbox	Gateway message trace and quarantine logs
T1059.001 PowerShell	An obfuscated script running on an endpoint	EDR, AMSI script scanning	Script block logging, Event ID 4104
T1003.001 LSASS Memory	A process opening LSASS to read credentials (the behavior behind LSASS credential dumping with Mimikatz)	EDR, LSA protection, Credential Guard	Sysmon Event ID 10 targeting lsass.exe
T1053.005 Scheduled Task	A scheduled task created for persistence	EDR	Security Event ID 4698 (needs the Audit Other Object Access Events subcategory), or Task Scheduler Operational log Event ID 106
T1558.003 Kerberoasting	Bulk service ticket requests for accounts with SPNs	Identity threat detection, SIEM rule	Domain controller Event ID 4769, especially RC4 (type 0x17)
T1490 Inhibit System Recovery	Shadow copy deletion with built-in tools	EDR ransomware protection	Sysmon Event ID 1 or Security Event ID 4688 with command-line logging
T1567.002 Exfiltration to Cloud Storage	Dummy data uploaded to external storage	DLP, web proxy	Proxy and egress logs, Sysmon Event ID 22 (DNS)

A blocked result should still raise an alert, or your SOC never learns of a real attempt. Detected means checking that the alert reached a person with enough context to act. Logged only is the cheapest gap to close: write the detection. Missed means fixing the telemetry first, then the detection.

Check how the BAS agent is excluded in your EDR: a broad allowlist, or an EDR that recognizes the tool rather than the behavior, turns misses into passes. Treat the console and its agents as privileged infrastructure, because they run on every endpoint.

What compliance frameworks and insurers accept

• PCI DSS v4.0.1. Requirement 11.4 calls for a documented methodology and internal and external penetration tests at least every 12 months and after significant change, by a qualified tester with organizational independence (PCI SSC document library). BAS does not meet it, though it can support 11.5.1 (intrusion detection) and 10.7.2 (prompt detection of failed security controls). See our PCI DSS penetration testing requirements.
• NYDFS Part 500. Section 500.5(a)(1) requires penetration testing from inside and outside the information systems’ boundaries, by a qualified party, at least annually. The original 2017 rule let entities with effective continuous monitoring skip it; the Second Amendment of November 1, 2023 deleted that option. Class A companies must also run EDR and centralized logging under 500.14(b), unless the CISO approves equivalent compensating controls, and BAS or a purple team is how you show those tools see lateral movement. More on our NYDFS 23 NYCRR 500 page.
• SOC 2. The Trust Services Criteria list penetration testing among the ongoing and separate evaluations in a CC4.1 point of focus. BAS can support monitoring evidence under CC7.2, but customers will still ask for your last third-party test. See SOC 2 penetration testing.
• Cyber insurance. AIG’s published CyberEdge ransomware supplemental questionnaire (Australian edition) lists BAS software, an in-house red team or annual internal penetration test, and an outside party simulating threat actors as separate select-all-that-apply answers to how you validate your controls. Our cyber insurance guide covers other carriers.

Presenting BAS evidence to an auditor

File the two as separate evidence, because they answer different controls. The penetration test report, retest and attestation letter go under the testing requirement: PCI DSS 11.4, NYDFS 500.5 or the SOC 2 evaluation criteria. BAS run reports go under monitoring and detection: PCI DSS 10.7.2 and 11.5.1, SOC 2 CC7.2 or NIST SI-4(9). Export dated BAS results that show a control failing, the ticket that fixed it and the passing re-run; that sequence is what shows the control operating over time.

Which one should you buy first?

Your situation	Start with
No EDR or SIEM, or nobody watching alerts	External and internal penetration tests. BAS measures detection you do not have yet.
PCI DSS, NYDFS or SOC 2 evidence is due	A penetration test scoped to the framework
SOC, EDR and SIEM in place, with detection engineers	BAS, alongside the annual penetration test
A red team showed your SOC missed the attack	A purple team assessment, then BAS to keep the fixes in place
You ship a SaaS product weekly	Application testing run as a program (PTaaS); BAS does not test your application. Our guide to continuous penetration testing explains the model
The board asks whether ransomware would be caught	A ransomware readiness assessment or a red team

What each costs

BAS platforms are sold as annual subscriptions, usually priced by agents or assets and the modules you enable, and vendors generally quote rather than publish prices. Budget for what is not on the invoice: agent upkeep, change approval to run scenarios in production, and detection engineering hours to act on the results.

Most Invadel engagements have a published starting price, and every price is fixed in writing from your scope before work starts:

Engagement	Starting price
External network penetration test	$4,200
Internal network penetration test	$6,000
Web application penetration test	$5,200
Ransomware readiness assessment	$6,000
Red team	$12,500
Purple team assessment	Quoted, fixed in writing
PTaaS program	Quoted, built from the published prices

Each penetration test comes with executive and technical reports, an attestation letter and a free retest of what you fix; the red team pricing page shows the tiers, and the cost calculator totals several tests.

How Invadel tests alongside BAS

• Send your BAS coverage with your scoping request. If your platform already shows what your EDR blocks, our testers do not re-prove it. The hours go to the way in, Active Directory paths, application logic and hosts your agents miss.
• Purple team sessions combine libraries and tradecraft. We run techniques from libraries such as Atomic Red Team and Caldera alongside hands-on operator work, mapped to ATT&CK, and record each as detected, logged but not alerted, or invisible. Your team tunes; we re-run.
• Every detection gap becomes a scenario. Load the techniques our report lists as invisible into your BAS schedule, and the platform tells you weekly whether the fix holds.

Testing is done by senior in-house specialists, never subcontractors, with onboarding within 24 hours of a signed proposal. Read a sample report first.

Frequently asked questions

Is breach and attack simulation the same as penetration testing? No. BAS is software that replays known techniques against your controls to see whether they block or detect them. A penetration test is a person finding and exploiting weaknesses in your environment to show what an attacker could reach.

Can breach and attack simulation replace an annual penetration test? Not for compliance. PCI DSS 11.4 and NYDFS 500.5 require penetration testing by a qualified tester, and NYDFS removed its continuous-monitoring alternative in 2023. For your own visibility, BAS covers the months between tests well.

Is BAS testing safe to run in production? Vendors design scenarios to be non-destructive, and CISA’s advisories recommend testing your security program in production. Still agree in writing which scenarios run where, warn your SOC so simulated alerts are not escalated as real incidents, and start with a pilot group of hosts.

What is the difference between BAS and red teaming? BAS runs known techniques on a schedule and scores each control. A red team is a covert, goal-driven operation by people who adapt to what they find. Our guide to red teaming vs penetration testing covers where each fits.

Do we need a SOC before BAS is worth buying? In practice, yes. Without EDR, centralized logging and someone to tune detections, BAS results have nowhere to go, and a penetration test will tell you more for the money.

How much does breach and attack simulation cost? BAS platforms are annual subscriptions, usually priced by agents or assets and by module, and vendors generally quote instead of publishing prices. Add the internal cost: agent upkeep and the detection engineering time to act on results.

Which is better for ransomware readiness: BAS or a penetration test? They answer different halves. A penetration test or ransomware readiness assessment shows whether an attacker could reach and encrypt what matters. BAS shows, week after week, whether your controls still catch the techniques named in ransomware advisories.

The short version

Breach and attack simulation tests, continuously, whether your defenses catch the techniques you already know about. A penetration test finds the ways in you do not know about, and it is what PCI DSS, NYDFS and your customers ask for. Add BAS once you have people to act on it, and keep the annual test either way. Scope your penetration test (external tests from $4,200, with a free retest of remediated findings, and every published starting price on our pricing page), or ask about a purple team assessment or a PTaaS program, which are scoped and quoted.