iconservicesagent CPU and RAM problems (Mojave)

Do the following:

1 - download and run Etrecheck.  Copy and paste the results into your reply. Etrecheck is a diagnostic tool that was developed by one of the most respected users here in the ASC and recommended by Apple Support  to provide a snapshot of the system and help identify the more obvious culprits that can adversely affect a Mac's performance.

Use the Add Text button to include the report in your reply:

Also assign Full Disk Access to Etrecheck so that it can get additional information from the Console and log files for the report:

2 - boot into Safe Mode, Use safe mode to isolate issues with your Mac, run there for a while and then reboot normally. Any improvement?

I had this problem on both Macs I have, an iMac 27" and a MBP from 2012. There seemed to be two different solutions on the separate computers, although I'll admit that I don't know if that's true. They showed the same symptoms, as noted: iconservicesagent goes bonkers and slows down the Mac to a crawl, with applications not responding as seen on the Activity Monitor. Sometimes a dogged approach to force quitting the iconservicesagent will temporarily stop its RAM hog routine, but it's no solution. I tried suggestions from users in this forum that I should write commands from Unix to half iconservicesagent, but I'm terrible at navigating around Unix, and the suggestions didn't work, anyway.

On the iMac, I serendipitously ran a scan of my drives using ClamXav, so see if it's a virus issue. ClamXav collected 4 suspicious files and quarantined them. I deleted the files and all went well since then with the iMac, but the MBP continued to have problems after I tried the same "solution" as I used on the iMac.

The MBP was a different story. I found that the MBP was acting up when I attached two external drives for copying files from one external drive to the other. As soon as I plugged one or both of the drives (both had nearly identical directories) to the MBP, I'd start getting the slowdowns with the web browser, the Finder, and another application failing to respond. Unplug them, and the machine ran fine. So I decided that I really didn't need all of the archaic files I had on these drives and erased both of them under the pretense that, with the hundreds of thousands of files on these drives, I'm likely getting some icon/resource corruption (some files were over 15 years old.) that's causing iconservicesagent to go nuts. So after erasing both external drives and copying all of my photo databases to one drive from the iMac, then moving that external drive to the MBP to copy those files to the second erased external drive, ALL WENT WELL, and I've no more iconservicesagent issues.

Basically, I have no idea what I'm doing, but can narrow the scope of troubleshooting just enough to find a solution without really knowing the underlying cause of the problem.

So I'm hedging my bets that the issue is corrupt resource data from files that iconservicesagent has extraordinary difficulty in resolving. We'll see if the problem returns after these maneuvers. As of now, all is well.

So there you go. I suggest that for those with similar problems, you can try my solution or monkey around with some troubleshooting tips. You might get lucky, because apparently Apple doesn't know that this issue exists, or they DO know, but don't have the investment in time or resources to address the issue on a system-wide basis.