I discovered these ".tm_" files today in mIRC's folder on the computer of a non tech-savvy user, while updating their mIRC. I never saw these files before, ever. There were like about 60 of these files over the course of a few months, looking at the date modified column. Some were a few KB big, but most were empty (0 bytes). A quick look inside the ones that had data in them revealed that they had mirc.ini config stuff in them. A Google Search led me here to this topic as I had no idea where this was coming from, other than suspecting some software on their computer that's causing this (because they have no scripts that write to files, only a few aliases and a small snippet that does some /CAP stuff). I ended up cleaning up (deleting) these files. No idea what software on their computer causes it, though.