Back in the iDrive days, i kept a somewhat scummy file stored in mine. It was an silly exploit developed in metasploit, mostly just a fun proof-of-concept .scr (windows screensaver) file that would take over a system on which it was run (this being related to my professional work). Anyway, it sat around there for a while until one day my Apple ID credentials were suddenly locked. I called up Apple and, after speaking to a confused front-line guy, i got on with an engineer that explained they thought my account has been compromised on account of the 'malware' they found stored on my drive. We all had a good laugh after i explained what was up. They restored the account and i removed the file.
All that to say: they might be checking your files, or at least the signatures your of files, for certain combinations... So keep it in mind.