Time Machine protects from ransomware?

Time Machine will not prevent ransomware, malware or adware. These all will be backed along with your TM backups. However if you choose to revert from a Time Machine backup previous to the malware attack it will be helpful.

As Tesserax says, scan with Malwarebytes to detect and remove malware.

Having recent "clean" backups of your computer, especially cloned copies of the Mac's internal hard drive is one way to recover from a ransomware infection. Time Machine backups would be part of that strategy ... but not the cloning part. That would require a different application, like Carbon Copy Cloner or SuperDuper!

I just did an Internet search on "How to avoid ransomware on Macs" and got dozens of articles that can be reviewed. Note: I would avoid those that are basically ads and review those from trusted sources.

You do not need an anti-virus program for your iMac, but I would suggest that you download and use Malwarebytes often to root out any potential infections.

Don't rely on Sophos. I would recommend uninstalling it. Anti-virus apps are renowned for identifying false positives and causing problems with Macs. They also will cause your Mac to take a hit on performance.

The only thing you can rely for Sophos is false positives when it is not causing conflicts with OS X. 3rd party Mac AV products have so far been proven to be ineffective with detecting Malware and Adware on Mac and never actually faced an actual Mac Virus so their reaction to one if it came into existence has never been documented.

If you are using Sophos to protect PC's on your network use a Windows AV product on the Windows device to do that so you are not causing potential and often serious issues.

3rd party Mac AV products have been documented on these forums as points of conflict with OS X/Mac OS's ability to manage itself through the securities updates Apple provides.

Updates to your OS and securities patches from Apple are the single best software defense on Apple Computers at this time.

Actually even the firewall is unnecessary if you are behind a router. Also, Mac's own built-in security features protect your Mac very well. I wasn't aware that Apple recommend Sophos. It would be nice to see some documentation, or did a rep in an Apple Store suggest that? I can see them suggesting it, if you were also running Windows. Of course, if you just look in the AppStore, they're selling all sorts of stuff that wouldn't be any good for your Mac.

I don't use either MBAM or Sophos but if you would reference where/how you've discovered that they conflict so that I may share the info, I'd appreciate it. If you can't, no worries.

Sophos has active "protection" whereas MBAM is only an on-demand scanner (at least for now). Are they detecting each other's signatures?

Sophos has active "protection" whereas MBAM is only an on-demand scanner (at least for now). Are they detecting each other's signatures?

MBAM only finds and removes Adware. It does no active scanning, which is not needed on a Mac. If you let yourself be tricked into installing Adware, MBAM usually can remove it. Unless Sophos installs Adware (certainly possible from my point of view), then MBAM would likely detect it.

As far as I know, there is no AV package that will detect and prevent you from installing Adware, though I know some Adware is detected and removed by Protect (or some other part of the OS).

While MacOS's built in Time Machine does not protect against this third party software such as Bitdefender Anti-malware does however prevent modifications to TM backups and allows you to set it so that it scans it for malware.

Thank you for the clarification.