Pdf a malware threat?

[Erhat]

I foolishly opened a pdf attachment that has me concerned. The email was addressed to me at an alternate address I haven’t used in a long time, and purported to be an invoice from a product order. The company name was similar to one I recently did business with, so I clicked on the pdf, which launched in Preview. This was in Thunderbird under macOS Catalina; I have email configured not to open linked content such as photos. Nothing unusual appeared when I opened the file — it just appeared to be an invoice.

With the pdf on Desktop, I ran Malwarebytes for Mac, which reported no threats. I copied the pdf onto a thumbdrive and took it to a Windows 10 system, where Malwarebytes for Windows similarly reported no threats.

But I’m still paranoid. A few weeks ago I received an email that had a Powerpoint attachment with a very definite Windows Trojan. What more can/should I do to run to ground whether there was any malware content not yet detected? Why would a bogus message like this be sent if it *doesn’t* contain malware? The email address that was used for me showed up some time ago as being among addresses hacked from a forum I formerly was a member of.

 

[Fishrrman]

Download MalwareBytes and run it:

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[Erhat]

Download MalwareBytes and run it:

Thanks, but as noted in my original post, I already did this, and it reported nothing. CleanMyMac also runs in the background on that Mac, and flagged nothing.

I’m just paranoid because the pdf attachment was sent to an old address of mine that I used only to access a forum whose user database I know was later hacked sometime ago. I’d speculate that if the pdf is infected it’s malware that targets Windows, but Malware for Windows also found nothing. So at this point I just want to take any additional steps to make sure the Mac that I opened the file on is ok before I continue to use it.