The Grinch Wants Your Data: Securing Your Environment in Holiday Season

As offices slow down, inboxes fill with out-of-office replies, and teams step away to recharge, cybercriminals do the opposite. The Christmas and New Year period consistently ranks as one of the highest-risk windows for cyberattacks.

Why? Because attackers understand the holiday mindset. Reduced IT staffing, slower approvals, and relaxed vigilance create the perfect conditions for exploitation.

This advisory explains why the holiday season is prime time for attackers and provides a practical, Microsoft-focused checklist to help ensure your organisation returns in January to business as usual—not a recovery operation.

1. Why the Holidays Are Prime Time for Attackers

Holiday attacks are not random; they are deliberate and strategic. Threat actors take advantage of the “skeleton crew” reality common during festive shutdowns.

They know that:

• Decision-makers are offline – Escalations, approvals, and crisis decisions are delayed while executives are on leave.

• Monitoring thresholds are relaxed – Alerts are often deprioritised to avoid waking on-call staff.

• Patching is paused – Change freezes leave known vulnerabilities exposed for weeks.

The Impact

• Breaches remain undetected for longer, increasing dwell time.

• Ransomware spreads quietly before being noticed.

• Financial fraud blends into end-of-year processing and reconciliation

2. Key Threats During the Holiday Period

a. Phishing & Social Engineering

The festive rush creates ideal cover for deception. Expect spikes in:

• Fake parcel delivery notices (Amazon, DHL, Australia Post)

• “End-of-Year Bonus” or HR-themed emails

Microsoft reality:Attackers increasingly bypass basic Exchange Online Protection by using

legitimate-looking SharePoint or OneDrive links to host malicious content.

b. Ransomware

Long weekends are a favourite launch window. Attackers often trigger encryption just before Christmas Eve, maximising pressure by threatening prolonged downtime when staff are unavailable.

c. Credential Theft & Identity Attacks

Holiday travel introduces “legitimate noise.” Logins from hotels or holiday homes can obscure:

• Password spraying

• Brute-force attempts

• lMFA fatigue attacks against Microsoft 365 and VPN access

  
  

d. The Unpatched Window

If a critical CVE drops on December 23, attackers assume remediation won’t happen until January.Internet-facing assets—VPN gateways, identity services, and email infrastructure—become prime targets.

3. Precautionary Measures: Before the Break

Preparation is your strongest defence. Before the last employee logs off, use your Microsoft security stack to harden the environment.

A. Identity & Access Control (Microsoft Entra ID)

1. Privileged Access ReviewUse Privileged Identity Management (PIM) to remove permanent admin rights and enforce just-in-time access.

   
   

2. MFA & Conditional Access Enforcement

   
   

   Make MFA mandatory for all users.

   Block sign-ins from high-risk geographies where you have no business presence.

   Require compliant devices (via Intune) for Microsoft 365 access

   
   

3. Disable Legacy AuthenticationTurn off IMAP, POP, and legacy SMTP to prevent password-based attacks.

B. Patch & Vulnerability Management (Intune & Defender)

• Protect Critical Infrastructure Ensure domain controllers, VPNs, firewalls, and identity services are fully patched.

  
  

• Microsoft Defender Vulnerability Management Identify and remediate any Critical vulnerabilities on exposed assets.

  
  

• Intune Update RingsConfirm update rings are active and no critical patches are stalled in “pending” status.

C. Backup & Recovery Readiness

• Azure Backup Protection Verify Soft Delete and Backup Immutability are enabled in Recovery Services vaults.

  
  

• Test Restores Perform a spot restore of a critical VM or file to validate recovery readiness.

D. Security Monitoring (Microsoft Sentinel)

• Reduce Alert Fatigue Disable low-value alerts and prioritise high-severity detections such as ransomware, identity compromise, or impossible travel.

  
  

• Update Notification PathsEnsure alerts reach on-call staff via mobile notifications or secondary email addresses—not unattended shared mailboxes.

E. Email & Endpoint Protection (Defender for Office 365 & Endpoint)

• Safe Links & Safe Attachments Confirm both are enabled to detonate suspicious content in a sandbox environment.

  
  

• Tamper Protection Ensure Tamper Protection is ON in Microsoft 365 Defender to prevent attackers from disabling security controls.

  
  

4. During the Holidays: “Eyes on Glass”

You don’t need a full team—just disciplined oversight.

• Daily Health Checks A 10–15 minute daily review of the Microsoft 365 Defender dashboard for high-severity incidents.

  
  

• Automated Response Leverage Defender’s Automated Investigation and Response (AIR) to contain common threats automatically.

  
  

• Strict Change Freeze Enforce a no-nonessential-changes policy. Any emergency change must be logged with a rollback plan.

5. Employee Awareness: Your Final Firewall

Before staff break for the holidays, send a short, clear reminder.

Subject: Holiday Security Reminder

Key points:

• Pause before clicking—delivery updates and e-cards are common lures.

• Verify urgent requests—especially gift cards or payment demands via SMS or WhatsApp.

• Report suspicious emails immediately using the Report Phishing button in Outlook.

6. Post-Holiday Actions

When normal operations resume:

1. Review Entra ID sign-in logs for anomalies or spikes during the break.

2. Revoke temporary access granted during the holiday period.

3. Resume standard patching and change cycles.

Key Takeaway

Cybercriminals don’t take holidays—defenders must plan for them.

A few hours of proactive preparation across Microsoft Defender, Entra ID, Intune, and Sentinel before Christmas can prevent months of remediation in the New Year. Holiday security planning isn’t optional—it’s essential.