"test_01." in drop location?

Why does the file "test_01." keep appearing in my drop location? It's due to System Monitoring!

This tiny file is uploaded to drop locations as a part of our System Monitoring. It is uploaded regularly to test the connectivity and availability of each drop location (the default is every 10 minutes), for each drop location that has Monitoring enabled. This can be disabled by an Administrator from the System Monitoring tab.