SentinelOne EDR Deployment
Enterprise Endpoint Protection at Scale

Engagement Overview

Executive Summary

The organization was running legacy signature-based antivirus with no behavioral detection, no centralized visibility, and no formal incident response process. Five security events had occurred in the prior 12 months — none were detected by tooling. Incidents were discovered by end users reporting performance issues or strange behavior, meaning average detection time was measured in days, not minutes.

The objective was to deploy SentinelOne Singularity with full behavioral AI detection, configure policies appropriate for a manufacturing environment (including OT-adjacent workstations where process disruption would halt production), and build a repeatable incident response workflow. MTTR was reduced from 48 hours to 6 hours within 60 days of deployment.

Phase 1 — Environment Assessment

Before any deployment, a complete endpoint inventory was pulled via Datto RMM to understand the environment:

• Total endpoints: ~100 (workstations, servers, production-floor terminals)
• OS baseline: Windows 10/11, Windows Server 2019, legacy Win7 terminals on production floor
• Existing AV: Webroot — outdated definitions, inconsistent deployment via manual installer
• Zero centralized telemetry — no SIEM, no log aggregation, no alert routing
• No formal IR process — security events discovered via helpdesk tickets

Endpoints were classified into three groups to guide policy design: production-floor machines (highest disruption risk — strict exclusions needed), office/admin workstations (standard policy), and servers (most aggressive detection, Vigilance mode).

Phase 2 — Deployment Planning

Policy design was the most critical step. A single policy applied to production-floor machines and servers alike would either cause false positive lockouts on industrial software or leave servers under-protected. Three distinct policies were designed:

• Server Policy: Detect + Protect mode, Vigilance MDR enabled, aggressive behavioral AI, auto-quarantine on critical threats
• Workstation Policy: Detect + Protect mode, standard behavioral thresholds, user notification on medium threats
• Production Floor Policy: Detect-only initially (no auto-remediation), whitelist signed manufacturing software binaries, escalate to human review before any action

Rollout strategy: staged over 3 weeks via Datto RMM MSI deployment — IT/admin machines first, then office workstations, then production floor last. Webroot was uninstalled 48 hours after SentinelOne confirmed healthy enrollment to avoid AV conflicts.

Phase 3 — Deployment Execution

Deployment proceeded across all 100+ endpoints over approximately 3 weeks. Key execution details:

• Datto RMM used for MSI package deployment, enrollment status tracking, and re-targeting failed installs
• Enrollment confirmed via SentinelOne management console — 98% completion within week 1
• 2 legacy production terminals required manual installation due to limited OS support
• EICAR test files used to validate detection and alert routing on each policy group
• Initial false positives from legacy manufacturing ERP software resolved via path exclusions and signed binary whitelisting over a 2-week tuning period
• Final false positive rate after tuning: <2%

Phase 4 — IR Workflow Design

The organization had never had a written incident response process. Post-deployment, a tiered playbook was built:

• P1 (Critical): Active ransomware, lateral movement, data exfiltration indicators — immediate network isolation via SentinelOne, escalate to security contact, 15-minute SLA to triage
• P2 (High): Credential harvesting, suspicious PowerShell, unauthorized admin activity — review within 1 hour, contain if confirmed malicious
• P3 (Medium/Low): PUA detections, policy violations, informational alerts — weekly review batch

SentinelOne Vigilance MDR was configured for server policy with automated network isolation on Critical threats. Alert routing was configured: P1 triggers SMS + email immediately; P2 triggers email to security contact within 30 minutes.

Phase 5 — Real-World Validation

Within 90 days of deployment, 5 security incidents were detected and contained that would have gone unnoticed under the legacy AV environment. One representative case:

SentinelOne flagged suspicious powershell.exe execution on an office workstation — process spawned from winword.exe (a macro-enabled document opened via a phishing email). Behavioral AI classified it as a credential harvesting attempt. Automatic network isolation triggered within 8 seconds of detection. Hash analysis confirmed Meterpreter-style payload. Endpoint cleaned, credentials for the affected user rotated, phishing email domain blocked. Total time from detection to clean: 4.5 hours.

Without SentinelOne, this incident would have been discovered days later when the user reported performance issues or when credentials were used to access corporate systems.

Outcomes

Metric	Before	After
Detection Time	Days (user-reported)	<15 minutes (SentinelOne alert)
MTTR	~48 hours	~6 hours
Security Incidents Detected	0 formally (discovered incidentally)	5 detected & contained
Endpoint Visibility	0%	100%
False Positive Rate	N/A	<2% after 2-week tuning

Findings & Recommendations

Finding	Severity	Recommendation
No behavioral detection capability	Critical	Deploy EDR with AI behavioral analysis (SentinelOne Singularity)
Zero incident response playbooks	High	Establish tiered IR playbook with defined SLAs and escalation paths
No centralized endpoint visibility	High	Deploy RMM + EDR management console with alert routing
Legacy AV — inconsistent deployment	Medium	Standardize endpoint security via RMM policy deployment
Production floor on same flat network	Medium	VLAN segmentation to isolate OT-adjacent machines (see FortiGate Refresh)

MITRE ATT&CK Mitigations

This EDR deployment addresses the following techniques by providing behavioral detection and automated containment:

Technique	ID	How SentinelOne Addresses It
Command and Scripting Interpreter	T1059	Behavioral AI detects anomalous PowerShell/script execution lineage
Data Encrypted for Impact (Ransomware)	T1486	Rollback capability + auto-isolation on ransomware behavioral signatures
Impair Defenses	T1562	Tamper protection prevents EDR agent modification
Obfuscated Files or Information	T1027	Static AI + behavioral engines detect obfuscated payloads pre-execution
Valid Accounts	T1078	Identity-based behavioral anomalies flagged via Vigilance MDR