Data Breach
Microsoft Exchange Data Breach
250K records exposed • January 2021
Chinese hackers found secret bugs in Microsoft email servers. They broke into 250,000 organizations around the world, including government offices, before anyone could stop them.
What Happened
Chinese state-sponsored hackers (HAFNIUM) exploited four zero-days in Microsoft Exchange to compromise over 250,000 servers worldwide, including US government agencies.
Attack method: ProxyLogon zero-day vulnerabilities (CVE-2021-26855)
What Data Was Exposed
Emails, Contacts, Calendars, Server access
Is your business exposed?
What to Do If You're Affected
- 1.
Patch Exchange servers immediately
- 2.
Run Microsoft Safety Scanner
- 3.
Check for web shells and persistence
Lessons for Businesses
- • On-premise Exchange is risky
- • Zero-days can be exploited at scale
- • Nation-states stockpile vulnerabilities
Sources
Related Breaches
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