On Apr 11, 2018, Microsoft released updates to address a security gap in the Microsoft Outlook. The gap allows an attacker to send a maliciously crafted email to steal the "hashed" password of the email recipient. An attacker with a hashed password can try to guess the actual password.
The stronger your password; the more complex the hash; the less likely for the attacker will be successful.
Thus, Information Security recommends the following:
1. Run Windows Update to keep your computer up-to-date and close the vulnerability.
2. Choose a strong password to ensure that your hashed password is extremely difficult to break. A passphrase (a password with 15 or more characters) is an example.
3. Don't click on any link unless you can trust the sender. This tip applies to all emails.