I wanted to practice some Java and Python and what better way for me than writing some RE tools. I decided on my SecuROM protected executable. While I was at it I loaded up the executable in Olly and even x64dbg and to my surprise it no longer ran under a debugger.
It took me a while to figure out that I had fiddled with Scyllahide's settings a few years back. I found out the reason it didn't work no more. A hook of NtUserFindWindowEx caused SecuROM to detect the debugger somehow, whether intentionally or it's a byproduct of something
So far, no clue but after I finish up my tooling I may find out what it is, could end up being a good anti-debug check.