Microsoft Cyberattack Targets SharePoint Servers in Global Zero-Day Breach

A growing threat to business and government IT infrastructure — what you need to know now

On July 21, 2025, Microsoft issued an emergency alert regarding a critical zero-day vulnerability in SharePoint Server actively exploited in the wild. The flaw (CVE-2025-53770) is part of a coordinated cyberattack targeting businesses, universities, government agencies, and energy companies worldwide.

According to Reuters and The Hacker News, at least 75 SharePoint servers have already been compromised, prompting international incident response efforts and urgent mitigation guidance.

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What is the SharePoint zero-day attack?

CVE-2025-53770 is a remote code execution vulnerability affecting:

• Microsoft SharePoint Server 2016
• SharePoint Server 2019
• SharePoint Subscription Edition

This zero-day enables attackers to execute malicious code remotely, steal encryption keys, and gain persistent access to critical systems, even after applying standard patches.

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Who is being targeted?

The attack has impacted a broad range of sectors, including:

• Government ministries and defense agencies in Europe, Asia, and the Americas
• University networks storing sensitive research data
• Energy and utility companies, compromising operational resilience
• Private enterprises with outdated or misconfigured SharePoint infrastructure

These victims have reported data exfiltration, unauthorized privilege escalation, and even signs of espionage-related activity.

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Key indicators of compromise (IoCs)

Cybersecurity teams should immediately investigate the following:

• Suspicious modifications in IIS logs or machineKey elements
• Lateral movement attempts using PowerShell or WMI
• Unauthorized privilege escalation in Active Directory
• Traffic anomalies or beaconing to unknown IP addresses

Microsoft’s telemetry shows that attackers are maintaining persistence by disabling security features and injecting memory-resident malware after gaining access.

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What Microsoft recommends

Microsoft has released an emergency patch, but also encourages these immediate actions:

• Suspicious modifications in IIS logs or machineKey elements‍
• ‍Install the July 2025 security update for all SharePoint servers
• ‍Rotate machine keys and restart IIS post-patching
• ‍Enable Antimalware Scan Interface (AMSI) for real-time threat blocking
• ‍Temporarily disconnect unpatched systems from the internet
• ‍Run threat detection scripts and perform forensic analysis

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We urge all organizations using on-prem SharePoint to take immediate action. Delayed response could lead to widespread compromise - Microsoft Security Response Center

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Strategic implications for cybersecurity leaders

1. On-prem systems are high-value targets

Despite the cloud-first movement, many organizations still rely on hybrid infrastructure. Attackers exploit this gap to bypass modern cloud defenses.

2. Zero-day attacks demand Zero Trust

Legacy VPNs, RDP gateways, and unsegmented networks are a liability. It’s time to rebuild architecture with Zero Trust principles.

3. Cyber hygiene must be a board-level priority

Incidents like this underscore the need for proactive vulnerability management, SOC visibility, and incident response drills — not just reactive patching.

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✅ How Apolo Cybersecurity can help

At Apolo, we help public and private entities reduce risk exposure with specialized services, including:

• SharePoint hardening and secure configuration audits
• Zero Trust framework implementation
• 24/7 SOC monitoring and incident response support
• Threat-Led Penetration Testing (TLPT) for real-world simulation
• Executive reporting for governance compliance

🔐 Request a free cybersecurity audit

Let our experts help you strengthen your defenses and stay ahead of the threat landscape.

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