What is the 'BaseSystem.dmg' File?
If you are not used to the macOS operating system and its features, then you might not be aware of some of the messages and filenames you are likely to encounter. Users appear to often wonder why they see a flashing window about a file named 'BaseSystem.dmg.' The good news is that users seeing this message typically do not experience any side effects, but they are suspicious about the flashing window which shows for just a second.
BaseSystem.dmg is Part of the Time Machine Tool
Thankfully, BaseSystem.dmg is not a malicious file and, in fact, it is part of a legitimate Mac feature, the Time Machine. Seeing the BaseSystem.dmg pop-up is perfectly normal while using the Time Machine utility.
Trying to search for BaseSystem.dmg on your computer will not show any results because this file has a short lifespan. Time Machine only creates it temporarily as a 'failsafe' in case something goes wrong. The purpose of the BaseSystem.dmg file is to create something like a restore point for your macOS. This way, if something with the backup process go wrong, Time Machine will be able to undo any unexpected changes and issues that may have occurred.
Do keep in mind that it is not uncommon for cybercriminals to abuse legitimate filenames and app names to conceal the presence of their implants. If you encounter the BaseSystem.dmg message while using Time Machine, then it is likely that this behavior is perfectly normal. If, however, you keep seeing this pop-up flash every now and then, then it might be a good idea to look into the issue. The best way to check for any problems is to run an up-to-date Mac security scanner.
