Flash error 16 when using latest Mac version (27.0.0.187) on Safari

[Kwajmeck]

Every couple of minutes, I get an error message that says that I am not using the latest version of Flash (when using Safari), and to download and update Flash.  I have used the link in the error message and have downloaded that software.  I have installed, restarted Safari as suggested (shutdown and restarted), and a few minutes later I get the same message.  I went to the Adobe web page and found a page that would check to see if I had the latest version;  same answer - I am using the latest version.

Please tell me what to do to solve this problem.

[_maria_]

Sounds like this is a malicious notification, and installer.  Flash Player update notifications don't display that often.  Please post a screenshot of the error dialog (https://forums.adobe.com/docs/DOC-7043#jive_content_id_How_do_I_attach_a_screenshot ). Does it show the link the file is downloaded from?

[Kwajmeck]

[_maria_]

The error in the screenshot is not related to Flash Player.  It appears to be related to Creative Cloud.  See Configuration error in Adobe Creative Cloud and AI Workshop: Error 16 - What To Do About It?   If you have further issues with this dialog, please post to the Adobe Creative Cloud forum as they are better able to assist you with this error.

If you get the Flash Player update notification error again, post a screenshot of that.

[Kwajmeck]

I changed all of the privileges for all users to "read/write', and restarted, as suggested in a link above: no change.  Then I found a spam task that  somehow get downloaded from a site that I was directed to, by a variation of the error 16 message, and discovered "Advanced Mac Cleaner" lurking in the background.  I deleted the app, and a message in a new tab appeared on Safari suggesting that I keep the app and clean up my machine with their app.  I declined, and restarted my machine.  Error 16 was gone but it was replaced with the attached error.  I'm suspecting that it is a residue from that spam/hacked-like app.  Any additional help would be appreciated.

[Kwajmeck]

Hi Maria.  Please read the comment above.  Because of the Error 1, Acrobat XI Pro will only let me open a file, but as soon as I touch it to read or save, I get the Error 1 and it crashes.  If I uninstall, I can only re-install with a 2 year old dmg and I can't use it because the license has expired.  I'm caught between a rock and a hard place.

[jeromiec83223024]

Nobody monitoring this forum is an Acrobat expert, but that said, it really seems like the machine is in a bad state.  The things you've tried are totally reasonable, and it hints that something else is probably going on.

As you noted above, it sounds like you had a malware problem.  I tend to agree based on what you're saying here.  I would not assume that the problem is gone just because your machine is no longer exhibiting obvious symptoms.  Malware authors test against anti-malware tools and "cleaners" too, and if they're targeting modern operating systems, they're going to generally be very capable engineers.

At best, whatever happened here left things in a bad state.  The forensic work of figuring out with confidence exactly what happened and how to unroll it is best left to the (very expensive) forensic specialists of the world.  It's generally not worth the time or expense unless you're a defense contractor or something.  It's far easier and cheaper for the layperson to just burn everything down and start over.

If it were me, and I were doing anything remotely sensitive with the machine (banking, healthcare, work, etc.), I'd be seriously thinking about a complete round of formatting the machine and reinstalling the OS and everything else from pristine sources, followed by an afternoon or rotating important passwords and/or adopting a password manager, just in case your keystrokes have been getting logged since you first encountered whatever that malicious payload was that you ran into.

Anyway, the general strategy would be to move your important data to either a USB hard disk or an online file service (Google Drive, Adobe Cloud, etc.) and/or back it up.  Most of the cloud services automatically scan for viruses, so that's a consideration.  Wipe the machine and install a current version of the OS (MacOS lets you boot into a recovery mode now, where it will just download and install the OS with nothing else required -- About macOS Recovery - Apple Support​ ).  Install a current antivirus, reinstall your applications, apply any and all available updates, and then go about restoring your data. 

If you have a ton of data, hopefully you have a time machine backup, and you can just roll back before the original infection occurred.  Since you haven't already done that, I'm guessing it's probably not in the cards.  Because there's a sketchy malware component to this story, I would not simply install over the top of the existing data.  You could, and it might fix the installation symptoms, but the issue if trustworthiness is another matter...

It's also worth pointing out that USB memory sticks can be vectors for malware, and you can infect a USB stick's firmware, such that it will then attempt to install malware on every machine the key is then inserted into.  If you rely heavily on memory sticks and have used one on this machine since the infection, you might think about retiring it with a hammer.  It's cathartic.  (Since your machine is already sketchy, there's no harm in pulling the data off it and putting it on storage that's less likely to re-infect your machine)

Of course, this all comes down to your personal paranoia level and risk tolerance, but identity theft can be expensive and tremendously inconvenient.  Reinstalling your operating system is not an ideal way to spend an afternoon or evening, but it's way better than many of the alternatives.