If your Apple Mac computer is more than a year old, then you need to pay special attention to this.

A major flaw has been found that leaves the door open for hackers to get into your computer and bury themselves deep within your BIOS (basic input/output system), which is the core of the computer that gives it life.

The vulnerability was first announced by a Portuguese man name Pedro Vilaca in his blog post last Friday.

But this is only applicable to people who purchased a Mac one year ago or earlier, CNN Money reports.

The scary part of this bug is that it buries itself deep within the system so that it is mostly undetectable. These Macs get infected when they go to sleep, then wake back up. This is what leaves the door open for attackers to come in and access your BIOS. When they're in, they can tamper with your core data code and could conceivably force your Mac into a coma.

"This is scary," Sarah Edwards, a forensic analyst at the SANS Institute, told CNN Money. "I would never see this. There could be funky stuff going on in the computer system, and I would never know why."

But there are some protections from this, because it is not an easy task for a malicious hacker. They would first need administrative access to the computer before it can embed itself. But when it does, it can go so deep that it may never be found.

Apple has not responded to news of this flaw, nor have they announced when there will be an update to fix it.

High value targets include banks, government entities, politicians and executives. The basic premise for these potential victims are anyone who would be most worth the time for spying on to get the information or monetary property for which they desire.