What Is Meant By IASB?

Here’s how to handle Internet Account Security Breach (IASB) alerts in Windows 11 (version 24H2 as of 2026). Works for both corporate and personal devices tied to Active Directory or Azure AD.

What's happening?

In Windows 11, an IASB alert (Internet Account Security Breach) pops up when Microsoft detects odd login attempts or unauthorized access on your Microsoft account. Think of it as Microsoft’s AccountGuard program keeping watch for credential stuffing, phishing, and brute-force attacks. The alert fires off when:

• Logins come from weird locations or devices
• Someone tries (and fails) to guess your password multiple times
• Microsoft finds your login details leaked in a third-party hack

(Nope, this isn’t the same as IFRS—that’s for accounting. IASB here is all about Microsoft’s security alerts.)

How do I fix it?

1. Check your Microsoft account right away
   1. Head to https://account.microsoft.com/security
   2. Sign in with your current password
   3. Look through the Recent activity section for devices or locations that don’t look familiar
2. Double-check those login attempts
   1. Under Security, open Review recent activity
   2. Watch for red flags: logins from strange countries, at odd hours, or on devices you’ve never seen
   3. Hit This wasn’t me if something looks off
3. Run a full malware scan
   1. Hit Win + S, type Windows Security, and open it
   2. Go to Virus & threat protection
   3. Pick Scan options > Microsoft Defender Offline scan > Scan now
   4. Restart when asked (the scan runs before Windows loads)
4. This scan catches sneaky rootkits and advanced malware that normal scans miss. Microsoft Support
5. Reset your Microsoft account password
   1. On the Security page, pick Change password
   2. Type your current password, then make a fresh one (12+ characters, mix of cases, numbers, symbols)
   3. Turn on Two-step verification if you haven’t already
6. Remove any devices you don’t recognize
   1. Back on the Security page, go to Advanced security > Manage devices
   2. Find and remove anything that doesn’t look right

What if the problem persists?

• Lock your account from another device: Grab a phone or another computer, go to https://account.live.com/acctinfo/security, and pick More security options > Lock my account. This kicks everyone out and forces re-authentication.
• Get help from Microsoft Support: Open the Get Help app (Win + Ctrl + F), search “account locked,” and Microsoft Support can fast-track security flags within 24 hours (as of 2026).
• Check if your email was in a breach: Pop over to Have I Been Pwned to see if your email’s been exposed. If it has, change all related passwords ASAP.

How can I prevent this in the future?

• Enable Two-Factor Authentication (2FA) on your Microsoft account. Go to Security > Two-step verification > Set up. Use the Microsoft Authenticator app or a hardware key. Microsoft Support
• Use a password manager like Bitwarden or 1Password to create and store unique passwords for every service. (Reusing passwords is a top way accounts get hijacked.)
• Keep an eye on Microsoft Defender for Endpoint (Windows 11 Pro/Enterprise only): Open Windows Security > Device security > Core isolation and turn on Memory integrity to block kernel-level attacks that steal credentials. Microsoft Learn
• Set up account alerts: In Security > Notification settings, turn on alerts for logins from new devices or locations.