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Hackers Use Compromised ConnectWise Credential to Sign In to 173 Microsoft 365 Tenants

A recent major cyber attack has shown just how easily hackers can slip into business accounts using stolen third-party software credentials. In this latest incident, attackers managed to get ahold of a single compromised password for ConnectWise—a popular IT management platform—and used it to quietly log into 173 different Microsoft 365 cloud environments. Because these kinds of tools are trusted by companies, hackers love targeting them to gain a backdoor into corporate networks without raising immediate suspicion.

For everyday users and business owners, stories like this highlight why staying vigilant about your email and digital accounts is more important than ever. Hackers frequently use compromised credentials to send convincing phishing emails from legitimate accounts, making it nearly impossible for the average person to spot a fake at first glance. If you ever receive an unexpected message—even one that looks like it came from a familiar IT service or colleague—you should never click links or download attachments blindly.

When something feels even slightly off, the safest move is to verify the message before taking action. You can simply forward any suspicious email to scan@report.mailforensis.com and get a plain-English threat analysis back in seconds. Staying secure doesn't have to be complicated, and having a quick way to check your inbox ensures you never fall victim to the next major credential-stuffing attack.

Got a suspicious email?

Forward it to scan@report.mailforensis.com and get a clear answer in seconds — free.

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