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Microsoft alerts users of massive phishing attack: What to do now

Windows phishing attack
(Image credit: Getty Images)

Microsoft has warned users about a persistent email phishing threat that targets users with a morbid, coronavirus-related lure and and a leading medical institution's likeness.

COVID-19 email scams have ran rampant since the pandemic started, with bad actors hoping to benefit from heightened fear and internet usage. The one the Microsoft Security Intelligence team is tracking claims to contain an updated death count from John Hopkins, which pioneered coronavirus maps and case tracking efforts.

Except, according to Microsoft, the email's Excel attachment doesn't just display a chart with the number of coronavirus-related deaths in the US — when opened, the hostile file prompts users to 'Enable Content.'

Once this action is carried out by an unsuspecting victim, the Excel file's malicious macros download and install the NetSupport Manager client using a remote access trojan, or RAT.

NetSupport Manager's remote administration tool then lets a hacker hijack the user's system even execute commands on it remotely.

The Microsoft Security Intelligence team issued this alert via Twitter, using a thread to explain that how a number of different dirty Excel files all trace to the same URL.

“The hundreds of unique Excel files in this campaign use highly obfuscated formulas, but all of them connect to the same URL to download the payload," Microsoft wrote. "NetSupport Manager is known for being abused by attackers to gain remote access to and run commands on compromised machines.”

Is this email a scam? How to protect yourself

Although the NetSupport Manager tool is useful for benevolent remote administration, it can be easily exploited by RAT hackers. 

If a bad actor accesses your system through NetSupport Manager, your entire computer is compromised. The hacker has the means to command your machine, install files and steal personal data.

You can protect your information and your device with a healthy dose of skepticism. Whenever you receive emails from people outside of your contact list, don't click on any internal links and examine the sender's email address.

Malicious addresses often contain misspelled words or random combinations of letters and numbers, too.

It could also help to install and run some of the best antivirus software, not just on Windows but on Mac and Android too. Most of the attacks we've seen in recent months are already well known and will be detected and stopped by AV software.