Office 365 Cybersecurity Consultancy — UK Microsoft 365 Setup, Hardening & Monitoring
Office 365 / Microsoft 365 is the most-used platform in UK businesses — and the most common entry point for cyber attacks. Most UK SMEs run M365 with conditional access, retention, and Defender misconfigured out-of-the-box. We deliver consultancy + secure setup, hardening, monitoring — the technical controls that convert an 'M365 default' tenancy into a regulated-firm-ready posture.
#1 platform
Microsoft 365 — the most commonly attacked platform in UK cyber incidents
~70%
of UK SMEs use M365 with default-out-of-the-box security settings
One-off
Office 365 secure setup + hardening engagement (UK SME 5-50 staff)
24/7
Gridisys managed SOC for Office 365 / M365 monitoring — no contract
Cybersecurity Consulting + 24/7 SOC Monitoring
Every Gridisys engagement is built on two pillars — strategic consulting to design the right controls, and managed SOC monitoring to keep them effective.
Cybersecurity Consulting
UK consulting engagements: risk assessment, security architecture, conditional access design, compliance (Cyber Essentials, UK GDPR, FCA PS21/3, NIS2), incident-response planning. Board-ready documentation, no jargon, no surprise invoices.
- Risk assessment + security architecture review
- Conditional access + Entra ID hardening design
- Cyber Essentials / UK GDPR / FCA / NIS2 compliance support
- Incident response planning + tabletop exercises
- Vendor + supply-chain security assessment
- Board / DPO reporting + evidence pack
Managed SOC Monitoring · 24/7
AI-augmented Security Operations Centre — continuous monitoring across Microsoft 365 / Entra ID, Defender, on-prem, and cloud. UK-based analysts, sub-hour triage on critical alerts. No long contract required.
- 24/7 SIEM monitoring — Microsoft 365, Entra ID, Defender, Azure, on-prem logs
- BEC + mailbox-compromise + OAuth grant abuse detection
- Suspicious sign-in + conditional access drift alerting
- Ransomware + lateral-movement detection from EDR + Defender
- Sub-hour triage on critical alerts, monthly ops report
- Optional + integrated with consulting engagements
Most engagements start with consulting (1-2 weeks), then SOC monitoring (ongoing ) keeps the controls effective.
Pricing tailored to your needs
Every engagement is scoped to your environment and requirements. Book a free consultation for a tailored quote — no obligation.
What we cover
Practical, board-ready consulting — no jargon, no surprise invoices.
M365 / Office 365 secure setup
From greenfield tenant build or hardening of an existing M365 tenancy: ~120-line baseline config across Entra ID, Exchange Online, SharePoint, OneDrive + Defender + Purview. Documented config pack aligned to NCSC M365 Secure Configuration + CISA M365 guide.
Conditional access design
Entra ID conditional access policies — MFA everywhere, geo-block, device compliance requirements, spouse-of-risky-sign-in patterns, EAP-to-admin-only, blocked-legacy-auth. We design the policy stack + break-glass accounts aligned to NCSC guidance.
Defender for Office 365 hardening
Defender for Office 365 Plan 1 / 2 configuration: anti-phishing policy, safe links + safe attachments, mailbox impersonation protection, ZAP enabled. Tuning false-positives vs false-negatives for high-value real-world phishing pattern coverage.
Mailbox BEC prevention
Specifically tuned to BEC patterns affecting UK SMEs (CFO impersonation, supplier bank change, lawyer chain compromise, 'invoice due' fraud): mailbox rules alert rules, finance mailbox restricted access, callback verification workflow, RM + finance training.
Microsoft Purview DLP + retention
Data Loss Prevention policies: credit card detection, NHS numbers, UK bank account numbers, UK passport numbers + custom sensitive info types. Retention labels aligned to UK GDPR + sector requirements (legal 7 years, finance 7 years / FCA PS21/3, healthcare lifespan).
M365 backup + ransomware resilience
M365 native backup may not be sufficient (recycle bin retention finits, Exchange Online mailbox corruption sometimes excluded from native restore). We architect third-party M365 backup covering Exchange, SharePoint, OneDrive, Teams with 4-6 hour restore target.
App governance + OAuth grant audit
Monitor OAuth grants across M365: flag high-privilege consents (Mail.ReadWrite, Files.Read.All, full mailbox access), audit + revoke stale grants, periodic review with stakeholders. Often missed but a primary Modern Compromise Vector.
Microsoft 365 E5 / E3 security review
For E3 / E5 licensed firms: assess whether your existing entitlement is fully utilised — many E5 security features (Defender for Identity, Defender for Cloud Apps, Purview Audit Premium) are underused on default tenancy. We document gap report on feature-to-licence match.
How we work
Scope + audit (Week 1)
Tenant health-check (GAP audit) — license posture, conditional access review, Defender status, OAuth grants inventory, retention baseline. Document specific gaps vs NCSC / CISA postures.
Remediate + harden (Week 1-2)
Implement ~120-line config baseline + conditional access policies + Defender tuning + DLP policies. Disable legacy auth, enforce MFA, configure break-glass admin.
Train + document (Week 2-3)
Run incident-response playbook with admins + finance (BEC callbacks). Document the secure-config pack as a CIO/DPO document for audit. Brief leadership on posture gains.
Monitor (ongoing — optional)
Managed SOC subscription covers 24/7 monitoring of M365 / Entra alerts, conditional-access drift, OAuth grant changes, mailbox-compromise indicators.
Sectors we protect
Office 365 hardened — M365 set up right, monitored 24/7
Free 30-minute consultation for IT leads and CIOs at UK SMEs. We do a sample tenant audit (any of: MFA / legacy auth / OAuth grants / Defender anti-phishing) and quote the hardening engagement.
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