Key Takeaways
- Annual security testing remains valuable for identifying weaknesses and providing detailed assurance within a defined scope.
- Large enterprises change continuously. New assets, suppliers, SaaS tools, accounts and detection rules can appear between tests.
- Security evidence becomes less reliable as environments change. Controls that worked during an assessment may not perform the same way months later.
- Attackers do not operate within testing windows. They adapt when routes are blocked and look for alternative ways into an organisation.
- The right testing frequency depends on risk, the pace of change and regulatory requirements. Continuous validation can complement annual testing where more current assurance is needed.
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Annual security testing remains valuable, but for large enterprises it may not provide enough assurance on its own. Systems, access and attacker techniques change between assessments, meaning an annual test shows how defences performed during a particular testing window, not necessarily how they perform today. Combining periodic testing with change-triggered assessments and ongoing security validation can help organisations maintain a more current understanding of their exposure.
What Does an Annual Penetration Test Actually Tell You?
An annual penetration test tells you how a defined scope performed against skilled testers during a particular testing window. Penetration testing can uncover exploitable weaknesses and demonstrate how vulnerabilities might be combined within an agreed scope.
However, its findings reflect the systems and conditions assessed during the engagement, rather than providing ongoing evidence of how the environment performs as it changes.
Penetration testing remains valuable for identifying vulnerabilities, understanding their potential impact and providing evidence to auditors and customers. But it is one part of a wider security testing programme, which may also include vulnerability assessments, configuration reviews, red teaming and detection and response testing.
What Changes in a Large Enterprise Between Annual Tests?
Between annual assessments, a large enterprise may add and retire assets, suppliers, SaaS tools, user accounts and detection rules. The environment that was originally tested can quickly become different from the one that exists today.
Changes introduced after a test may not be covered by its findings, leaving organisations relying on evidence that no longer fully reflects their environment.
Typical changes include:
- New systems and SaaS tools adopted outside the formal testing cycle
- Joiners, leavers and changes to user access
- New suppliers and third-party integrations
- Detection rules that are changed or retired
- Newly disclosed vulnerabilities
- Legacy assets and old credentials that are no longer regularly reviewed
In a large enterprise, these changes happen at scale. Different business units may also be assessed on different dates, creating a patchwork of security evidence rather than one current picture.
See our Nothing Stays Scoped threat report to explore cases involving a forgotten legacy server, an unrotated credential and a new AI tool, illustrating how overlooked or newly introduced exposures can create opportunities for attackers.
What Is Control Drift?
Control drift occurs when security controls become less effective or stop working as intended as systems, configurations, access or operating conditions change.
It can be difficult to identify because there may be no obvious failure. A control may have worked during the last assessment, but that evidence becomes less reliable as the environment changes.
Statements about security often describe what was true at a particular point in time. Asking a follow-up question helps establish how current that evidence really is.
| What we say | What to ask |
|---|---|
| “We detected the red team.” | When? |
| “We fixed the findings.” | Was it retested? |
| “Our controls stopped the attack.” | What happened when the attacker changed route? |
| “Our SOC performs well.” | Under what conditions? |
One way to identify potential gaps is to classify key security assumptions as proven recently, proven but stale, assumed or unknown.
Anything that is stale, assumed or unknown deserves further investigation.
How Do Evolving Attacker Techniques Affect Annual Testing?
Attackers do not work to a testing window. They follow opportunities, adapt when a route is blocked and exploit weaknesses in systems, people and processes.
A test conducted within a fixed scope may not reveal the alternative attack paths that become available later.
A real-world example from one of our engagements shows why testing an attacker’s ability to adapt matters:
- A new exposure appeared. Operators discovered a remote access portal that had not existed two weeks earlier, alongside leaked credentials.
- The first route was blocked. A leaked password used against the new portal was stopped by MFA. This was a positive result and was recorded as evidence.
- The operators tried a trusted route. They obtained an MFA reset through the helpdesk.
- The login went unnoticed. The SOC’s identity logs recorded the activity, but no alert was raised and nobody responded.
- The fix was retested. The organisation closed that route and tightened its alert rules. When the same route was tested again three weeks later, it was detected within minutes and blocked.
Blocking an attack route is a positive result, but it doesn’t necessarily mean the wider attack has been stopped. An adversary may change tactics, exploit a trusted process or look for another way in.
Realistic attack paths often involve more than technical vulnerabilities. Attackers may exploit human behaviour, trusted processes and gaps in detection alongside weaknesses in infrastructure. Testing these elements together provides a fuller picture of how an attack could progress.
Our Built to Return threat report also explores cases where closing an initial entry point did not prevent attackers from regaining access.
When Is Annual Testing Enough?
Annual testing may provide sufficient assurance for some systems where change is limited, risk is lower and additional testing is not required by customers or regulators.
However, large enterprises often operate environments with different levels of criticality and change, making a single annual testing schedule unlikely to suit every system.
Signs that annual testing may not be enough on its own include:
- Findings are remediated but not retested
- Acquisitions, platform migrations or supplier changes occur between assessments
- You rely on an MDR provider or outsourced SOC but have not validated whether suspicious activity is detected, understood and acted upon
- Critical systems or business processes change frequently
- A regulator or customer expects more frequent assurance
Regulation can establish a minimum testing requirement, but meeting that minimum does not necessarily provide a complete picture of security.
For example, under the EU’s Digital Operational Resilience Act (DORA), financial entities covered by the relevant provisions must ensure that appropriate tests are conducted at least annually on ICT systems and applications supporting critical or important functions. Certain designated financial entities must also undertake threat-led penetration testing at least every three years, subject to supervisory requirements.
These are different testing obligations, and DORA does not require every relevant system to undergo an annual penetration test.
Where annual testing is a minimum requirement, organisations still need to consider whether additional validation is appropriate for their risk and rate of change.
What Can Large Enterprises Do Between Annual Tests?
Between annual assessments, large enterprises can use a combination of activities to maintain a more current understanding of their security posture.
- Retest what you fix. Confirm that remediation changes the outcome, rather than simply marking a finding as closed.
- Test after major change. New platforms, acquisitions and supplier integrations may justify additional testing before the next annual assessment.
- Scan for known weaknesses. Regular vulnerability scanning helps identify newly disclosed vulnerabilities and missing security updates.
- Monitor the external attack surface. Identify unmanaged assets, forgotten domains and exposed services as they appear.
- Test detection and response. Purple team exercises and adversary emulation can assess whether the SOC detects suspicious activity, understands its significance and responds effectively.
These activities answer different questions, so they are often most effective when combined.
Penetration testing provides detailed assessment of defined systems and applications. Vulnerability scanning identifies known weaknesses. Adversary emulation goes further by testing how an attacker might combine weaknesses, exploit trusted processes and pursue objectives over time.
Keep Your Evidence Current with WRAITH
WRAITH is OmniCyber’s human-led continuous adversary emulation platform, combining ongoing adversary campaigns, continuous exposure discovery and integrated threat intelligence.
Experienced Red Team operators pursue realistic attack paths over time, adapting as new opportunities emerge and testing whether security teams can detect and respond to attacks under normal operating conditions.
Unlike a scheduled assessment, WRAITH’s campaigns are designed to be unannounced, allowing organisations to assess how their technology, people and processes respond without advance preparation.
WRAITH complements penetration testing by providing continuous validation between scheduled assessments. It is also designed to replace traditional, time-bound red team engagements with ongoing adversary activity.
WRAITH also won Outstanding New Cyber Security Product at the 2026 Cyber OSPAs.
Explore the WRAITH Continuous Adversary Emulation Platform to understand how it works.
Related Questions
Does passing a penetration test mean we are secure?
No. A penetration test provides evidence of how a defined scope performed during a particular testing window. It does not guarantee that the environment remains secure as systems change or that detection and response will work against every attack.
Is continuous testing a replacement for annual penetration testing?
No. Penetration testing provides detailed assessment of defined systems and applications, while continuous adversary emulation tests how attacks could unfold across an organisation over time. WRAITH complements penetration testing but is designed to replace traditional, time-bound red team engagements.
How often should a large enterprise test its security?
Testing frequency should reflect the criticality of systems, the pace of environmental change, the organisation’s threat exposure and any regulatory or contractual requirements. Annual testing may be an appropriate baseline for some systems, while significant changes or higher-risk environments may justify more frequent or continuous validation.
What is continuous security testing?
Continuous security testing involves ongoing or repeated security assessments that help organisations understand how their defences perform as systems and threats change. Different approaches include vulnerability scanning, automated validation and human-led adversary emulation.
Not sure how current your security evidence is? Book a WRAITH Demo to see how continuous adversary emulation can help you understand how your defences perform over time.
Jennifer Goulbourne
Jennifer is a Digital Marketing Executive at OmniCyber Security, where she's responsible for engaging the company's existing customer base across digital channels and creating helpful resources on threat intelligence and security operations for cybersecurity professionals and business leaders.
