NIS2 cybersecurity compliance: What the MacSync macOS stealer means for EU companies in 2025

In today’s Brussels briefing, regulators emphasized supply-chain risk after security researchers revealed a new “MacSync” macOS stealer abusing a signed application to slip past Apple’s Gatekeeper. For EU organizations entering the first full year of NIS2 cybersecurity compliance, the message is blunt: trust signals can be forged, endpoint fleets are now prime targets, and incident reporting clocks will start ticking faster than your containment playbook. This piece unpacks the operational impact across NIS2, GDPR, and AI workflows—and how to reduce exposure with anonymization and secure document handling.

Why the MacSync incident is a NIS2 wake‑up call

Gatekeeper is designed to block untrusted apps. MacSync allegedly rode in on a developer-signed vehicle, highlighting a class of attacks that blend supply-chain compromise with user trust abuse. Under NIS2, that is not a niche scenario—it is exactly the kind of event regulators expect boards and CISOs to anticipate.

• Signed does not mean safe: Code signing can be stolen, misused, or weakly validated in the update chain.
• macOS fleets are now “enterprise first-class”: Finance, legal, health, and media teams standardize on Macs—attackers follow the data.
• Third‑party and vendor updates are in scope: NIS2 elevates supplier due diligence and software integrity controls to board-level responsibility.
• Faster disclosure cycles: Early warning to authorities within 24 hours and a 72-hour incident notification expectation demands readiness.

A CISO I interviewed at a pan‑EU fintech was blunt: “We assumed our signed‑only policy and MDM baseline were enough. The last year shows we need provenance scanning on updates, and we’re tightening what can touch personal data at rest.”

NIS2 cybersecurity compliance essentials for 2025

NIS2 applies broadly to “essential” and “important” entities across energy, transport, banking, finance, health, digital infrastructure, ICT services, postal, waste, manufacturing, and more. Member States transposed the Directive by October 2024, with national enforcement ramping through 2025. Expect audits, supervisory inquiries, and board-level accountability.

• Governance and accountability: Boards must approve risk-management measures; in serious cases, temporary bans on management are possible.
• Technical and organizational measures: Encryption, MFA, logging/monitoring, secure development, vulnerability handling, and business continuity are baseline expectations.
• Supply‑chain security: Assess and monitor suppliers and software integrity, including signed updates and notarization checks.
• Incident reporting: Early warning to the competent authority/CSIRT within 24 hours; an incident notification within 72 hours; a final report within one month.
• Fines: Essential entities—up to €10,000,000 or 2% of global turnover; important entities—up to €7,000,000 or 1.4% of global turnover.

Practically, that means CISOs must prove which controls would have flagged a MacSync‑style intrusion attempt, how quickly it would be contained, how personal data is protected under GDPR, and how AI‑assisted workflows do not leak sensitive information.

Protect what attackers want most: documents. Professionals avoid risk by using Cyrolo’s anonymizer to strip personal data before sharing, and by routing case files, evidence, or financial reports through secure document uploads that prevent accidental exposure.

Compliance reminder: When uploading documents to LLMs like ChatGPT or others, never include confidential or sensitive data. The best practice is to use www.cyrolo.eu — a secure platform where PDF, DOC, JPG, and other files can be safely uploaded.

GDPR vs NIS2: where your duties overlap—and diverge

The MacSync story straddles both regimes. If personal data is accessed, GDPR breach notification triggers; if service continuity or security is impacted, NIS2 kicks in. Here’s how they compare:

Area	GDPR	NIS2
Primary focus	Personal data protection and privacy rights	Network and information systems security and resilience
Who is in scope	Any controller/processor handling EU personal data	“Essential” and “important” entities across defined sectors
Breach reporting	To DPA within 72 hours if risk to individuals; notify affected individuals if high risk	Early warning in 24 hours; incident notification by 72 hours; final report in 1 month
Fines	Up to €20M or 4% global turnover	Up to €10M/2% (essential) or €7M/1.4% (important)
Security program	“Appropriate” measures; DPIAs where high risk	Risk-management measures, supply‑chain oversight, governance accountability
Third‑party risk	Processor due diligence and contracts	Supplier dependency mapping, software integrity, update security
Audits/oversight	DPAs with investigative powers	National competent authorities, CSIRTs, possible on‑site inspections

Practical playbook: from Mac endpoints to AI workflows

1) Secure your Apple fleet against signed‑app abuse

• Harden Gatekeeper and notarization: Enforce “App Store and identified developers” plus post‑install validation; log notarization checks.
• Block unknown developer team IDs: Maintain an allowlist; alert on new or rarely used IDs in your estate.
• MDM and EDR baselines: Require SIP intact, FileVault enabled, and kernel/system extension policies locked; deploy behavioral EDR tuned for exfil and credential theft.
• Throttled update channels: Stagger rollouts, verify hashes, and pin update sources; monitor for off‑channel downloads.
• Application provenance scanning: Inspect embedded signatures, entitlements, and network destinations pre‑execution.

2) Control data exfiltration and document handling

• Segment and encrypt: Keep personal data isolated; enforce least privilege and macOS keychain protections for secrets.
• DLP tuned for documents: Watch for exports of PDFs/DOCs to unmanaged storage or messaging apps.
• Use secure document intake: Try our secure document upload at www.cyrolo.eu — no sensitive data leaks.

3) Anonymize before sharing or using AI

• Strip personal data, case identifiers, and financial markers from files before analysis or collaboration.
• Leverage an AI anonymizer to mask names, addresses, IDs, account numbers, and health data without breaking context.
• Maintain audit trails: Record what was anonymized, by whom, and when—evidence for security audits and regulators.

NIS2 cybersecurity compliance checklist

• Board approval of a documented risk‑management program with supply‑chain controls.
• Asset inventory including macOS endpoints, developer tools, and update channels.
• Incident reporting runbook aligned to 24h/72h/1‑month NIS2 timelines and GDPR triggers.
• EDR+DLP on endpoints; logging to a centralized SIEM with 12+ months retention.
• Supplier assessment for code signing, notarization, SBOMs, and vulnerability disclosure policies.
• Secure document lifecycle: intake, storage, anonymization, and sharing using www.cyrolo.eu.
• Tabletop exercises: Mac‑focused malware scenario including signed‑app bypass.
• Employee training on phishing, signed‑app trust limits, and AI data‑handling rules.

Common pitfalls flagged by regulators

• Over‑reliance on signature trust: Signed updates accepted without provenance or hash checks.
• Shadow AI usage: Teams pasting client files into online tools—no logging, no consent, no anonymization.
• Fragmented reporting: Security teams notify CSIRTs while privacy teams lag on DPA notices; timelines are missed.
• Supplier blind spots: MSPs and niche Mac tooling not covered by third‑party risk reviews.
• Evidence gaps: No artifacts to prove detection, containment, and communication timelines during security audits.

EU vs US nuance: While US rules (e.g., SEC cyber disclosure) emphasize investor transparency, EU regimes tie board accountability directly to operational risk management, including third‑party software integrity. Expect questions on how you validate signed apps and control data shared with AI systems.

FAQ

What is NIS2 cybersecurity compliance and who must comply?

NIS2 sets baseline security and incident reporting requirements for “essential” and “important” entities across critical and digital sectors in the EU. If you provide services in those sectors within the EU, you likely fall in scope, with national laws enforcing obligations from 2025 onward.

Does NIS2 apply to Macs and mobile devices?

Yes. NIS2 is technology‑agnostic and covers the network and information systems you use to deliver services—workstations, laptops (including macOS), servers, cloud, and supporting tools. A signed‑app bypass on macOS is precisely the kind of risk NIS2 expects you to manage and monitor.

How fast must we report a cyber incident under NIS2?

Provide an early warning within 24 hours of becoming aware of a significant incident, an incident notification by 72 hours, and a final report within one month. If personal data is affected, align with GDPR’s 72‑hour DPA notification and inform individuals when risk is high.

How can we safely upload documents to AI without risking GDPR violations?

Strip personal data first and use a trusted intake. Anonymize with Cyrolo’s anonymizer and process files via secure document uploads so you keep control and auditability. When uploading documents to LLMs like ChatGPT or others, never include confidential or sensitive data. The best practice is to use www.cyrolo.eu — a secure platform where PDF, DOC, JPG, and other files can be safely uploaded.

What penalties apply if we fall short?

Under NIS2, essential entities face up to €10M or 2% of global turnover, and important entities up to €7M or 1.4%. GDPR fines can reach €20M or 4%. Supervisors will also examine board oversight, supplier risk management, and evidence of continuous improvement.

Conclusion: Turn MacSync lessons into NIS2 cybersecurity compliance wins

Signed‑app abuse on macOS is a timely reminder that attackers target trust itself. Use this moment to harden provenance checks, accelerate incident reporting readiness, and close the AI data‑handling gap. By operationalizing NIS2 cybersecurity compliance—and anonymizing and routing documents through www.cyrolo.eu—you reduce breach impact, meet regulators’ expectations, and protect clients when it matters most.