We hear a version of this story regularly: a business fires its IT provider or MSP for poor service, brings in a new firm, and moves on. What often gets skipped is the step in between — verifying the old provider didn’t leave anything behind.
An outgoing MSP typically holds admin credentials across your entire environment — servers, firewalls, email, sometimes your backup systems. When that relationship ends on bad terms, or even a merely lukewarm one, there’s no guarantee every credential was rotated, every remote access tool was removed, or every script they installed was accounted for. Most of the time nothing malicious happened. Occasionally, it did — and the business doesn’t find out until months later, usually when something else goes wrong and the incident response team finds an access point nobody remembered existed.
In practice, the residue from an MSP transition tends to cluster into a few recognizable categories: dormant admin accounts that were never deprovisioned, remote access tools (RMM software, VPN profiles) that remain installed and callable, scheduled tasks or scripts nobody on the new team recognizes or can explain, and configuration changes — firewall rules, DNS entries, forwarding rules — that don’t match any documented baseline. None of these are necessarily malicious on their own. Collectively, and left unexamined, they’re an open door nobody’s watching.
A post-transition threat hunt is a diagnostic pass through your network and endpoints specifically looking for what a departing provider might have left behind: dormant admin accounts, unexplained remote access tools, scheduled tasks nobody on the new team recognizes, and configuration changes that don’t match documented baselines. [“The Silent Breach: Why ‘No Alerts’ Doesn’t Mean ‘No Intruder”] covers the broader case for this kind of proactive review even outside a provider transition specifically.
The ideal window is between the old contract ending and the new one truly starting — before the new provider inherits an environment they didn’t build and can’t fully vouch for. Waiting until after the new provider has been operating for months makes it harder to distinguish what the old provider left behind from what’s changed since.
This isn’t an accusation against your old provider. It’s a baseline security assessment for your new one. Most new IT firms will tell you the same thing we will: they’d rather start from a verified-clean environment than inherit an unknown one and get blamed for whatever surfaces later. A documented, independent baseline at handoff protects everyone — the business, the outgoing provider’s reputation, and the incoming team’s liability — by establishing exactly what existed at the moment of transition.