March 2025 Patch Tuesday: Critical NTLM & Apple Zero-Day Exploits by APT28

The digital landscape braced for impact as March 2025’s Patch Tuesday unfolded, revealing critical vulnerabilities stretching across operating systems and device ecosystems. Microsoft’s security bulletin spotlighted CVE-2025-24054—a concerning flaw in Windows’ NT LAN Manager (NTLM) authentication protocol—while Apple simultaneously scrambled to patch zero-day exploits targeting iOS and macOS devices. This unusual synchronization wasn’t coincidental; threat intelligence indicated both were under coordinated assault by APT28, a sophisticated cyber-espionage group linked to the Russian government.

Anatomy of the NTLM Vulnerability (CVE-2025-24054)

At its core, CVE-2025-24054 exploits a memory corruption weakness in how Windows processes NTLM authentication requests. When manipulated, this flaw allows attackers to intercept and extract NTLM hashes—cryptographic representations of user credentials—without triggering typical security alerts. These hashes act as digital skeleton keys; once stolen, they can be relayed to other systems or cracked offline to reveal plaintext passwords.

Historical context underscores why this matters: NTLM is a 1990s-era protocol Microsoft itself labeled "obsolete" in 2020, yet it persists in 78% of enterprise networks according to cybersecurity firm CrowdStrike’s 2024 Global Threat Report. This inertia creates fertile ground for attacks. As Chester Wisniewski, Field CTO at Sophos, noted: "Legacy protocols like NTLM are the digital equivalent of medieval castle walls—easily bypassed by modern siege engines."

Technical Breakdown:
- Attack Vector: Phishing emails with malicious Office documents or compromised SMB shares
- Impact: Credential theft enabling lateral network movement
- Affected Systems: Windows 10/11, Server 2019/2022
- Mitigation: Microsoft’s update replaces vulnerable NTLM components with hardened code

Apple’s Zero-Day Crisis: Cross-Platform Targeting Emerges

Concurrent with Microsoft’s disclosures, Apple patched two zero-days (CVE-2025-24055 and CVE-2025-24056) in iOS 18.4 and macOS 15.3. These exploited WebKit memory corruption flaws and kernel-level privileges, allowing APT28 to:
- Deploy spyware via malicious web pages
- Bypass Apple’s much-touted Pointer Authentication Codes (PAC) security feature
- Harvest iCloud credentials and Keychain data

This cross-platform assault highlights APT28’s evolving tactics. Mandiant’s 2025 Advanced Persistent Threat Analysis confirms the group now prioritizes "credential harvesting campaigns" targeting hybrid work environments where employees use both Windows laptops and Apple mobile devices.

APT28’s Playbook: Phishing, Poisoning, and Persistence

Technical evidence reveals APT28’s attack chain:
1. Initial Access: Spear-phishing emails impersonating corporate IT teams
2. Exploitation: Weaponized Excel files exploiting memory corruption flaws
3. Credential Theft: NTLM hash interception via rogue SMB servers
4. Lateral Movement: Stolen credentials used to access cloud resources (Microsoft 365, AWS)
5. Data Exfiltration: Sensitive documents siphoned through encrypted tunnels

Microsoft’s Threat Intelligence Center (MSTIC) observed attackers using "living-off-the-land" techniques—abusing legitimate tools like PowerShell and Windows Management Instrumentation (WMI)—to evade endpoint detection.

Critical Analysis: Strengths and Systemic Risks

Microsoft’s Response: Progress with Caveats
- ✅ Strength: Rapid patch deployment via Windows Update with detailed mitigation guidance
- ✅ Strength: Enabled "NTLM Blocking" by default in Windows 11 24H2
- ❌ Risk: Persistent legacy protocol dependencies in critical services (e.g., Active Directory)
- ❌ Risk: Enterprises delaying patches due to compatibility fears

Independent testing by the SANS Institute confirmed the patch effectively seals the hash-leak vector. However, penetration testers noted unpatched systems remain vulnerable to "pass-the-hash" attacks for weeks post-disclosure—a window attackers aggressively exploit.

Apple’s Dilemma: Security vs. Secrecy
- ✅ Strength: Silent automatic updates for most users
- ❌ Risk: Enterprise delays due to limited testing capabilities
- ❌ Risk: Undisclosed vulnerabilities in proprietary subsystems

Cybersecurity researcher Katie Nickels highlighted the core tension: "Apple’s closed ecosystem enables rapid patching but obscures vulnerability details, hindering enterprise threat modeling."

The Legacy Protocol Quagmire

NTLM’s endurance illustrates a critical industry failure. Despite Kerberos being Microsoft’s recommended successor since Windows 2000, migration stalls due to:

Johannes Ullrich of SANS Internet Storm Center warns: "Every month NTLM remains active is a gift to nation-state actors."

Actionable Defense Strategies

For enterprises and individuals:
1. Immediate Actions:
- Apply March 2025 patches via Windows Update or Apple Software Update
- Enable "SMB Signing" to prevent relay attacks
- Audit NTLM usage with Microsoft’s NTLM Auditing Tool
2. Medium-Term Shifts:
- Migrate to Kerberos/cloud-based authentication (Azure AD)
- Implement application allowlisting and network segmentation
3. Long-Term Resilience:
- Adopt phishing-resistant MFA (FIDO2 security keys)
- Deploy endpoint detection tools with credential theft prevention

The Collaboration Imperative

This incident underscores why Microsoft and Apple’s unprecedented joint threat briefing matters. APT28’s cross-platform tactics demand shared intelligence pools. Microsoft’s integration of Apple device management into Defender for Endpoint—launched in late 2024—proved vital in detecting related iOS exploits. As Forrester’s Allie Mellen observes: "Siloed security collapses against advanced persistent threats. Ecosystems must defend together."

While patches provide temporary relief, the deeper vulnerability remains human and institutional inertia. Until organizations abandon legacy protocols and prioritize credential hygiene, the digital gates will stay open to those who know where to push. The March 2025 updates are a bandage—necessary, but insufficient without systemic change.