Managed Microsoft 365 Security Monitoring
Microsoft 365 is the most targeted platform for email fraud and account takeover in the UK. Defender generates the alerts. Our UK SOC investigates them, 24 hours a day, every day of the year. Inbox rule manipulation, OAuth consent abuse, BEC payment redirect attempts: we detect what automated filters miss, and we respond before your Finance team sees the fraudulent invoice.
Your MSSP sends alerts. We resolve them.
Most managed security providers forward Microsoft 365 alerts to your inbox and call it monitoring. Precursor operates a 24/7 UK SOC that investigates every alert, contains confirmed threats in real-time, and delivers monthly board-ready reporting. Office 365 email security that works around the clock.
Book a Scoping CallMicrosoft 365 Security Monitoring:
Coverage and Detection
Managed email security operations backed by UK SOC analysts. We ingest Unified Audit Logs, Defender for Office 365 alerts, Azure AD sign-in events, Microsoft Graph API telemetry, and DLP policy violations. Every alert is triaged by a UK-based L2 analyst, not just an automated rule.
Email Threat Detection
Advanced monitoring of Exchange Online and Defender for Office 365 to detect phishing, malware delivery, and account takeover via email. Detection examples: inbox rule created to forward mail matching invoice to an external address; display name spoofing; ZAP bypass indicators. Log sources: Unified Audit Log, Defender for Office 365 P2 alerts, Message Trace.
Business Email Compromise
BEC is the most financially damaging form of cyber fraud in the UK. We detect it at the infrastructure level: Set-InboxRule events, New-InboxRule via OWA or PowerShell, display name spoofing where the sender domain mismatches the executive name, and unusual email volume patterns from low-volume accounts.
Data Loss Prevention (DLP)
Monitoring DLP alerts for sensitive data shared externally via email, SharePoint, OneDrive, or Teams. Detects accidental leaks and intentional data exfiltration by malicious insiders or compromised accounts. Covers PII, PHI, financial data, and custom DLP policies.
Compromised Account Detection
Identifying mailbox abuse after account takeover. We monitor for: OAuth app consent grants with Mail.ReadWrite or Files.ReadWrite.All permissions; impossible travel events in Azure AD sign-in logs; legacy authentication on accounts with MFA disabled. Log source: Microsoft Graph API, Azure AD/Entra ID.
SharePoint Security Monitoring
Detecting mass downloads, unusual sharing activity, and external sharing of sensitive documents. Triggers: download of 100+ files in 30 minutes; sharing with unapproved external domains. Log source: FileAccessed, SharingLinkCreated events.
Teams Security and Governance
Monitoring Microsoft Teams for malware shared via chat, external guest abuse, sensitive data shared in channels, and suspicious app installations. Detects attackers using Teams as a command-and-control channel or lateral movement vector within your M365 tenant.
Office 365 Email Security Monitoring
Committed response times. Named contacts. No reduced staffing overnight.
UK Human Analyst Coverage
Critical alerts (confirmed BEC, account compromise, active exfiltration) receive immediate analyst triage, every hour of every day.
Named Contact SLA
Your named security contact is notified within one hour of confirmed threat, by phone. Same SLA on bank holidays.
Time to Live Monitoring
From contract signature to 24/7 monitoring. Graph API integration, baseline configuration, and policy tuning complete.
Microsoft 365 Security and Compliance Reporting
Board-ready reports delivered on the first business day of each month. Metrics your CISO can present to the board and your auditors can accept as evidence.
From Sign-Off to 24/7 Protection
We connect to your M365 tenant via Microsoft Graph API read-only permissions and are monitoring within one working week. No agent installs. No changes to your user environment. No downtime for your team.
Most organisations spend 3-6 months hiring and training a single security analyst. We deliver a full SOC team monitoring your M365 tenant in five business days, at a fraction of the cost of one in-house hire.
From contract sign-off to live 24/7 monitoring. API integration, baseline configuration, and policy tuning completed within one working week.
Read-only API permissions. No agents to deploy, no endpoints to reconfigure, no user training required. Your IT team grants access once. We handle the rest.
A single Tier 2 SOC analyst costs £40,000-£55,000/year in salary alone, providing 40 hours of weekly cover. Our service delivers a full team 24/7/365 from £900/month.
Engagement Workflow
Structured to minimise operational friction and maximise the value of the testing window.
Microsoft 365 Integration
We connect to your Microsoft 365 tenant via Microsoft Graph API read-only permissions and Defender for Office 365. Log sources include Unified Audit Logs, Defender alerts, Exchange transport rules, and DLP policy violations. No agent installs. No changes to your user environment.
Baseline and Policy Tuning
Establishing normal communication patterns, external sharing behaviours, and approved third-party apps. We tune Defender for Office 365 policies to reduce alert fatigue while maintaining strong detection coverage. Alert thresholds are tuned per tenant during this phase.
24/7 Threat Monitoring
Continuous monitoring for phishing, malware, BEC, data exfiltration, and account compromise. Our UK SOC reviews Defender alerts and correlates them with Azure AD, endpoint, and network telemetry. Critical alerts receive immediate analyst triage. You are notified promptly on threat confirmation, by phone to your named contact.
Incident Response and Containment
When a threat is confirmed, we assist with email purges (deleting phishing emails from all mailboxes), disabling compromised accounts, revoking malicious OAuth grants, and investigating the scope of data access. Monthly executive report delivered on the first business day of each month.
Procurement Requirements
Fixed monthly pricing with no per-incident fees. No hardware procurement. No multi-year lock-in. All monitoring, triage, and incident response is performed by UK-based analysts in our Newcastle SOC. Data never leaves the UK.
The Closed-Loop
Approach.
M365 monitoring works best when paired with identity threat detection and offensive security validation. Our penetration testers use SOC threat intelligence to simulate phishing and BEC attacks against your tenant, confirming that your defences catch real adversary techniques.
Explore Full MDR PlatformFull Services Catalogue
Comprehensive penetration testing services tailored to your environment.
Internal Testing
Post-perimeter assessments targeting Active Directory, lateral movement, privilege escalation, and segmentation validation from inside your network.
Ready to stop watching alerts pile up?
Book a free 30-minute scoping call. We assess your M365 tenant configuration, confirm monitoring scope, and provide a fixed monthly quote. No obligation. No hidden fees for incidents.
Managed Microsoft 365 Security: Common Questions
Pricing, coverage, SLAs, and how managed M365 security compares to operating Defender in-house.
Managed Microsoft 365 security starts from £900/month. Pricing depends on user count and service scope. Defender for Office 365 licensing is separate (Microsoft subscription). We provide fixed monthly quotes after understanding your user count and M365 configuration.
Defender for Office 365 is excellent technology but does not provide managed security operations: (1) Defender generates alerts but does not investigate them - you need analysts to triage, investigate, and respond 24/7, (2) Sophisticated phishing and BEC attacks regularly bypass Defender's detection - human analysts catch what automation misses, (3) Defender does not monitor Teams, SharePoint sharing activity, or OAuth consent grants comprehensively, (4) DLP alerts require investigation and response - Defender does not remediate, (5) Out-of-hours attacks (the majority of BEC) will not be addressed until your team returns, and (6) Defender cannot purge phishing emails from all mailboxes automatically - SOC intervention is required. Most organisations use Defender as a telemetry source while outsourcing 24/7 monitoring and response to specialist SOC providers.
We monitor Exchange Online (email), SharePoint Online, OneDrive, Microsoft Teams, Defender for Office 365, Azure AD/Entra ID (authentication and identity), Microsoft Graph API telemetry, and DLP policies. Coverage spans the full Microsoft 365 tenant: Exchange Online, SharePoint Online, OneDrive, Microsoft Teams, Azure AD/Entra, Defender Alerts, DLP Policies, and OAuth App Grants.
Yes. Business email compromise (BEC) is the most financially damaging form of cyber fraud targeting UK organisations and one of our core detection areas. A typical BEC attack starts with a compromised mailbox: the attacker gains access via a phishing email or password spray, creates an inbox rule to hide reply emails, and then waits - sometimes for weeks - reading internal threads to identify the right payment request to intercept. We detect BEC at the infrastructure level, not just the content level. Specific signals we monitor: inbox rule creation via OWA or PowerShell (Set-InboxRule, New-InboxRule events in the Unified Audit Log), display name spoofing where the sender display name matches an executive but the sending domain does not, OAuth consent grants to third-party applications with mail read/write permissions, and unusual email volume patterns from accounts that typically send low volumes. When we detect a BEC indicator, we alert your named contact immediately and can assist with account containment, inbox rule removal, and retroactive email triage to identify whether the attacker has already sent fraudulent communications. Pricing starts from £900/month.
When a phishing email bypasses Defender and is reported by a user or detected by our SOC, we immediately purge it from all mailboxes using tenant-wide email purge capability, block the sender domain, and analyse the email to improve detection rules. We also provide guidance for users who interacted with the email.
Yes. We monitor OneDrive for mass downloads, unusual sharing activity (especially external sharing of sensitive files), and ransomware indicators such as rapid file encryption patterns matching known ransomware extensions. Large-scale file operations by a single user account are flagged for analyst review.
Yes. We provide monthly executive security reports covering incidents detected, mean time to detect and respond, DLP violations, account compromise indicators, top threat types, and risk trends. Reports are formatted for board presentation and delivered on the first business day of each month. These support compliance requirements for ISO 27001, GDPR, and industry-specific regulations.
Critical alerts - confirmed compromised accounts, active BEC, or data exfiltration in progress - receive immediate analyst triage, 24 hours a day including weekends and bank holidays. We escalate to your named contact promptly on confirming a threat, by phone for high-severity incidents.
Yes. Our Security Operations Centre is based in Newcastle, UK. All monitoring, triage, and incident response is performed by UK-based analysts. No data is processed or transferred outside the UK. This supports GDPR compliance and data residency requirements for regulated sectors including financial services, healthcare, and legal.