47
Misconfigurations
Identified
Defender
For M365 configured
Conditional access
Enforced for all users
DLP policies
Data loss prevention active
Secure Score
Measured and improved
Entra ID Hardening & Conditional Access
M365 security starts with Entra ID. We configure Conditional Access policies to enforce MFA, block legacy authentication, require compliant devices, and implement sign-in risk policies. Privileged accounts are protected with PIM. Legacy authentication protocols: the most common path to M365 account compromise: are blocked.
Microsoft Defender for Office 365 Configuration
Defender for Office 365 (MDO) provides email protection beyond basic spam filtering. We configure Safe Links, Safe Attachments, anti-phishing policies, and impersonation protection. DKIM, DMARC, and SPF records are verified and hardened to prevent domain spoofing and email-based attacks.
Microsoft Purview Data Loss Prevention
M365 Purview DLP prevents sensitive information from leaving the organization through email, Teams, SharePoint, and OneDrive. We configure DLP policies for the data types your organization needs to protect: credit card numbers, Social Security numbers, health information, and custom sensitive data patterns.
Microsoft Sentinel & Defender XDR Integration
Microsoft Sentinel and Defender XDR provide SIEM and extended detection and response for M365. We configure data connectors, analytics rules, and automated response playbooks so security events from M365 are detected and investigated efficiently without requiring manual log review.
Microsoft Secure Score Optimization
Microsoft Secure Score measures your M365 security posture across identity, devices, apps, and data. We review your current Secure Score, prioritize the highest-impact improvements, and implement the configurations that raise your score while aligning to your business requirements.
Teams & SharePoint Security Configuration
Teams and SharePoint are common sources of accidental data exposure: guest access too permissive, external sharing unrestricted, sensitive files in public channels. We configure Teams and SharePoint security policies to restrict external sharing, control guest access, and apply sensitivity labels to protect sensitive content.
What Makes Us Different From Others
- Full M365 Stack Coverage We secure the complete M365 security stack: Entra ID, Defender for Office 365, Purview, Teams, SharePoint, and Sentinel: not just Exchange Online.
- Email Authentication Hardening DMARC, DKIM, and SPF configuration is included in every M365 engagement. Domain spoofing is one of the most common and preventable email threats.
- BEC Prevention Focus Business Email Compromise causes more financial loss than any other cybercrime type. We configure anti-impersonation, anti-spoofing, and conditional access specifically to block BEC attack patterns.
- Compliance Evidence Built In M365 Purview compliance center configurations are documented to satisfy SOC 2, HIPAA, and PCI DSS requirements for data protection and access control.
- Secure Score Baseline and Target We document your Secure Score before and after each engagement so you have measurable evidence of security improvement for leadership and auditors.
Our AWS environment had grown organically for three years and nobody had ever done a security review. garrisonOne found 47 misconfigurations in a single assessment: public S3 buckets, overly permissive IAM roles, unencrypted data at rest. Everything was remediated in six weeks and we passed our SOC 2 cloud controls section without a single finding.
Client results
See how we have helped
Financial Services
Accounting Firm — IAM Automation
Manual offboarding across 14 systems took two days. garrisonOne automated the full user lifecycle with HR-driven provisioning and role-based access, cutting offboarding to 10 minutes.
14
Systems under IAM
10m
Offboarding time
100%
MFA coverage
Industry focus
Industries we serve
Related Services: Cloud Security | Azure Security | Entra ID Services | Managed SOC
Frequently asked questions
What are the most common Microsoft 365 security failures?
The most common M365 security failures are: no MFA or conditional access enforcement (allowing password spray attacks to succeed), legacy authentication protocols enabled (bypassing modern MFA), no DMARC/DKIM/SPF records (enabling domain spoofing), overly permissive external sharing in SharePoint and Teams, missing Defender for Office 365 anti-phishing configuration, and no monitoring or alerting on suspicious sign-in activity.
What is Microsoft Secure Score?
Microsoft Secure Score is a measurement of your M365 security posture. It assigns points for security configurations across identity (Entra ID), devices (Intune/Defender for Endpoint), apps (Defender for Office 365), and data (Purview). A higher score indicates more security controls are in place. Secure Score also provides prioritized recommendations for improvement.
What is Business Email Compromise (BEC)?
Business Email Compromise is a type of cyberattack where attackers compromise or spoof a business email account to deceive employees, customers, or partners into transferring money or sensitive information. BEC causes more financial loss than any other cybercrime type according to FBI IC3 data. M365-specific BEC prevention includes anti-impersonation policies, DMARC enforcement, and conditional access.
What is DMARC and why does it matter for M365?
DMARC (Domain-based Message Authentication, Reporting, and Conformance) is an email authentication standard that instructs receiving mail servers how to handle emails that fail SPF or DKIM authentication checks. A DMARC policy of p=reject prevents attackers from sending emails that appear to come from your domain: preventing domain spoofing attacks against your customers and partners.
What is Microsoft Defender for Office 365?
Microsoft Defender for Office 365 (MDO) is an email security service that protects against phishing, malware, and business email compromise in Exchange Online. It provides Safe Links (URL rewriting and time-of-click scanning), Safe Attachments (sandboxing of email attachments), anti-phishing policies, and impersonation protection for executives and key personnel.
How long does an M365 security configuration take?
A focused M365 security hardening engagement covering Entra ID, Defender for Office 365, Purview DLP, and Teams/SharePoint security typically takes two to four weeks for a mid-size organization. Larger organizations with complex compliance requirements or Sentinel deployment may take four to eight weeks.
Resources
Company
Contact
- US: 4752 Euclid Rd Suite 11,
Virginia Beach, VA 23462 - India: Orchard Street, Sector 61,
Gurgaon, Haryana - Phone: (301) 825-5518
- info@garrisonone.com
