A huge cyberattack has recently targeted Microsoft 365 accounts, with hackers making more than 81 million login attempts in just two weeks. While that number sounds alarming, there's some good news: only a small number of accounts were actually compromised.
So, what happened, and should you be worried?
What is Microsoft 365?
Microsoft 365 is the service many people and businesses use for email, documents, calendars, and cloud storage. If you use Outlook, Word, Excel, Teams or OneDrive, chances are you're using Microsoft 365.
Because it contains so much valuable information, it's a popular target for cybercriminals.
What did the hackers do?
The attackers used a technique known as password spraying.
Instead of trying hundreds of passwords on one account (which usually locks the account), they tried a few common passwords across millions of different accounts. This makes it harder for security systems to spot the attack.
The hackers also used usernames and passwords that had already been leaked in previous data breaches. If someone reused an old password, there was a chance it would still work. Researchers also found that the attackers took advantage of a weakness in the way some organisations had configured their security, allowing them to bypass extra login checks in certain situations.
Was the attack successful?
Yes, but only to a limited extent.
Security researchers found that 78 Microsoft accounts across 64 organisations were successfully accessed during the campaign. While that is a relatively small success rate compared to 81 million login attempts, it shows that even a few weak passwords or poorly configured security settings can leave organisations vulnerable.
Should users be worried?
There's no need to panic, but this attack is a good reminder to take your online security seriously.
If you use Microsoft 365 for personal email or work, there are a few simple steps that can greatly reduce your risk.
- Use a strong, unique password for every account.
- Turn on two-factor authentication (2FA), so a password alone isn't enough to log in.
- Don't reuse passwords from other websites.
- Be cautious of emails asking you to log in or verify your account.
Why two-factor authentication matters
Two-factor authentication (sometimes called 2FA or multi-factor authentication) adds a second layer of protection.
After entering your password, you'll usually be asked to approve the login using an app or a code sent to your phone. Even if someone steals your password, they still can't access your account without that second step.
The bottom line
Cyberattacks like this happen every day, and they're becoming increasingly automated. Hackers aren't usually targeting individuals personally—they're looking for easy opportunities.
The good news is that simple habits, such as using unique passwords and enabling two-factor authentication, can stop the vast majority of these attacks before they succeed.
We support business and consumer clients who use Office 365. This latest incident is another reminder that good online security doesn't have to be complicated—it just needs to be used consistently.
If you feel like you maybe having an issue with your Microsoft 365 account or another tech issue, then don't hesitate to get in touch with one of our friendly team.
