“Internal” and “external” penetration testing answer two different questions about your security. External testing asks: can an attacker break in from the internet? Internal testing asks: once they are in, how far can they go? Both matter, and understanding the difference helps you scope testing that reflects how real attacks actually unfold.
External penetration testing
An external pentest targets your internet-facing perimeter — public web applications, VPNs, mail servers, exposed services, and cloud assets — simulating an attacker with no prior access. It answers whether your perimeter can be breached and how. Given that Iranian groups like Fox Kitten specialize in exploiting unpatched, internet-facing systems, external testing is essential for Israeli organizations.
Internal penetration testing
An internal pentest assumes the attacker is already inside — through a phished employee, a compromised laptop, or a malicious insider — and tests what they can achieve from there. It focuses on lateral movement, Active Directory and identity weaknesses, privilege escalation, network segmentation, and access to sensitive data. This is where many organizations are dangerously exposed, because perimeter defenses get the attention while the internal network stays flat and trusting.
Why you need both
Real attacks combine the two: an adversary breaks the perimeter, then pivots internally toward valuable data. With attacker breakout times now under 30 minutes, the speed at which they move internally is decisive. External testing reduces how easily they get in; internal testing reduces how much damage they can do once they are in. Testing only one leaves half the picture dark.
Scoping considerations
- Define targets clearly: which IP ranges, applications, and network segments are in scope.
- Decide the starting assumption for internal tests — assumed breach is the most realistic.
- Coordinate with your monitoring team so the test also validates whether your SOC detects the activity.
Persist Security performs both external and internal penetration testing and broader security assessments, and can run them against your managed SOC to confirm detection as well as prevention. Contact us to scope the right combination.
