Topic starter
16/01/2026 5:38 pm
TL;DR: Legacy Active Directory, service accounts, and insecure authentication protocols remain a primary path for compromised credentials, lateral movement, and ransomware because most enterprises still lack full visibility into service accounts, according to Silverfort and NHIMG research. Security-first authentication and inline blast-radius controls matter because residual identity risk does not disappear while migration projects remain incomplete.
Editorial analysis by NHI Mgmt Group, based on content published by Silverfort: “Secure in spite of legacy: The IAM leader’s guide to controlling identity risk”.
Key questions
Q: Where does legacy identity risk fail when service accounts are not fully visible?
A: It fails at governance, because unseen service accounts cannot be owned, reviewed, or constrained with confidence.
Q: Why do service accounts and legacy authentication paths increase ransomware risk?
A: Because attackers prefer identity paths that already have trust, reach, and persistence.
Q: What are the signs that residual identity controls are not actually reducing exposure?
A: The clearest signs are long onboarding cycles, unclear account ownership, continued use of insecure protocols, and controls that only exist after a migration project finishes.
Practitioner guidance
- Map every legacy service account to an owner and purpose Build a current inventory of service accounts, Active Directory-linked identities, and application-specific credentials, then assign accountable owners for each one.
- Enforce inline challenge rules at authentication Require additional verification for access from suspicious locations, unmanaged endpoints, or unusual session patterns, even when the target system itself cannot be changed.
- Restrict non-human accounts to known business use Constrain service accounts to the systems, tasks, and time windows they repeatedly need, and block out-of-pattern usage that would expand lateral-movement options after compromise.
Bottom line: Legacy identity estates remain active attack surfaces because service accounts and insecure protocols still carry production access.
Explore further
View Full Forum → | NHI Foundation Course → | Our Services → | Read the full analysis →
This topic was modified 5 days ago by NHI Mgmt Group
06/10/2026 11:42 pm
Legacy identity risk is a containment problem, not a migration problem. The governing issue is that critical access paths remain live while modernisation projects crawl forward. That means the security outcome depends on what can be enforced in place, not on how quickly systems can be replaced. Practitioners should treat residual identity exposure as an operational control issue, not a future-state architecture discussion.
A few things that frame the scale:
- Only 5.7% of organisations have full visibility into their service accounts, according to the Ultimate Guide to NHIs.
A question worth separating out:
Q: Should teams prioritise migration or containment when legacy systems still run the business?
A: Containment first, migration in parallel. If the business depends on fragile legacy systems, security teams need controls that reduce identity blast radius now rather than treating modernisation as the only acceptable path. Migration is the destination, but containment is what makes the journey safe enough to continue.
👉 Read our full editorial: Mastering legacy identity risk without waiting for migration