Just saw this earlier:
tidbits.com
Not good. Note that near the end of the article, a recommendation for Malwarebytes appears. I run it sometimes, but I also have ClamXAV installed on both of my Macs. However, I do not have it running in the background. I typically do a virus scan for both of my Macs once a month, first downloading and running Malwarebytes, then launching and running ClamXAV. Never had an issue.
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Antivirus Maker Avast Sold Data on Millions of Users - TidBITS
Motherboard and PCMag have teamed up to expose antivirus maker Avast’s practice of collecting and selling data on millions of users.
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Not good. Note that near the end of the article, a recommendation for Malwarebytes appears. I run it sometimes, but I also have ClamXAV installed on both of my Macs. However, I do not have it running in the background. I typically do a virus scan for both of my Macs once a month, first downloading and running Malwarebytes, then launching and running ClamXAV. Never had an issue.