Day-1 Integration Security Lab
The deal closed this morning and the business wants the two companies wired together by Friday. Now the hard part: what do you connect, what do you isolate, do you federate identity, and how do you triage the risk you just inherited? Run day-1 security integration and make each call under an assume-compromise posture — isolate first, assess before you extend trust, never federate into a directory you have not vetted, and keep the integration reversible until the acquired estate is proven clean. Each decision shows you why.
Pair this drill with the free M&A Day-1 Security Integration Checklist — the document that records the pre-connect gates, identity decisions and 30/60/90 plan you practise here. Educational drill, not legal or security-engineering advice.
The real job. More noise, a tighter clock.
The acquisition just closed and the business wants the two companies wired together by Friday. You run day-1 security integration. Work 10 board-room decisions — connect vs isolate, triage the inherited risk, the identity and domain-trust calls, the 30/60/90 sequence — and make the call a post-incident review would find defensible, then see why. You are graded on how many you get right against the clock.
What this lab is
- A free, browser-based decision drill on DAY-ONE security integration of a just-closed acquisition: work ~14 board-room decisions about what to connect vs isolate, how to triage inherited risk, and the identity and domain-trust calls.
- The governing posture is assume-compromise: you isolate first and earn trust through assessment — you do not join the networks or federate identity on close day just because the deal is legally done.
- You practise the real traps: running a compromise assessment before extending trust, not federating into an unvetted directory, forcing privileged resets, inheriting an undisclosed breach, resisting "integrate fast" pressure, and keeping integration reversible.
- This is post-close integration security — distinct from pre-deal due diligence. Each decision reveals why the defensible answer is right, and you are graded S–D on how many you call correctly against the clock.
- Educational decision drill — not legal or security-engineering advice. Pair it with the free M&A Day-1 Security Integration Checklist.
Frequently asked questions
What is the Day-1 Integration Security Lab?
A free, in-browser decision simulation that drops you into the morning an acquisition closes. You own day-1 security integration and work through board-room decisions — connect or isolate the networks, federate identity or not, how to triage the inherited attack surface, what to do about privileged credentials and inherited data — and each one has a single defensible answer under an assume-compromise posture, revealed after you lock in your call.
How is this different from M&A due diligence?
Due diligence happens before the deal closes and asks whether to buy and at what price. This lab is about the day after close: you now own the acquired environment, its risk and possibly an in-progress breach, and you have to decide what to connect, what to isolate, and in what order to integrate — without turning the acquired company’s unknown risk into your risk overnight.
Why isolate first instead of connecting on day 1?
On close day you have no verified picture of the acquired estate. Connecting the networks or federating identity immediately makes their unknown risk — stale domain admins, an undisclosed intrusion, an exposed perimeter — your risk instantly. Assume-compromise means you keep the environments separated, run a rapid compromise assessment and harden first, then extend trust only to what you have vetted.
Is this legal or security advice?
No. The lab is an educational drill. Apply the real decisions to your specific acquisition with your own security, legal and privacy advisers — inherited data obligations and breach liability in particular are fact- and jurisdiction-specific.