An annual penetration test captures a single snapshot of your external footprint on one particular day of the year, nothing more and nothing less. The trouble is that most businesses change their external footprint constantly and often invisibly, adding new subdomains, spinning up marketing microsites, deploying new cloud services, and quietly retiring old ones, frequently without any formal record kept of the change at all. By month three, that annual snapshot is very often already meaningfully out of date.
Change is constant, testing rarely is
A new product launch might add three new subdomains and a payment integration within a single two-week sprint. A marketing campaign might spin up a landing page hosted somewhere entirely outside the usual infrastructure, built quickly by an external agency and then largely forgotten about the moment the campaign itself ends. None of these individually feels like a major security decision at the time it happens. Collectively, though, they represent a genuinely moving target that a once-a-year test simply cannot keep pace with, however thorough it was on the day.
This is the exact gap that ongoing external network pen testing is specifically designed to close over time, rather than a single test performed once and then filed away until the following year rolls around. Continuous or more frequent testing catches new exposures close to the point when they actually first appear, rather than discovering them eleven months later once an attacker has already had ample time to find the very same gap first and exploit it quietly.
What continuous testing actually looks like
It does not need to mean a full manual engagement running every single week without any pause at all. A sensible approach combines automated monitoring that flags new assets and configuration changes the moment they appear, together with periodic deeper manual testing at sensible intervals spread across the year. Together the two approaches give you both breadth and genuine depth, rather than forcing an uncomfortable choice between the two extremes.
William Fieldhouse has seen the annual-only approach fail in practice more than once, sometimes expensively.
“A client had a perfectly clean annual test back in January, then launched a brand new customer portal in March that nobody thought to have tested separately at the time. It sat exposed with a genuinely serious flaw for months on end until their renewal test finally caught it during the following January cycle a year later.”
— William Fieldhouse, Director of Aardwolf Security Ltd
That kind of gap is entirely avoidable in practice, and it is not really a testing failure so much as a scheduling one at its core. The annual test did exactly what it was designed to do on the day it actually ran. Nobody had built a proper process to flag that a major new system had gone live in between cycles and genuinely needed its own dedicated look before the next renewal date eventually arrived on the calendar.
Match your testing cadence to your pace of change
If your business ships new features and services regularly throughout the year, your testing schedule should honestly reflect that same pace rather than defaulting blindly to whatever the calendar happens to say. Finding the best pen testing company partner for ongoing, flexible testing rather than a single annual box-tick exercise means new exposures get caught while they are still genuinely new, not eleven months into their exposed lifetime online.
Juan Mitchell