You might be wondering if your computer data is safe from hackers when you set the system to go to sleep at the end of the day. When in sleep mode, the computer disables many of the components necessary for a hacker to be able to get in to your computer. Most importantly, a sleeping computer is not able to maintain an active network connection that is necessary for a hacker to be able to infiltrate your system.
Sleep Mode and Wake-Up Command
Sleep mode, also known as standby mode, is a relatively inactive mode in which the computer shuts down all non-essential components and runs essential ones with minimal power. The computer behaves as if it is off when in sleep mode and it provides just enough power to keep whatever it was running when it was put to sleep in the system RAM. A computer in sleep mode can be restored with a wake-up command by either pressing the power button, pressing a keyboard button, clicking a mouse button or by a scheduled system task. Wake-up commands restore the computer to the state it was in when it was put to sleep as opposed to restarting Windows.
A computer's best defense against hackers when it is in sleep mode is that it naturally severs any connection with a network and the Internet by disabling the devices that establish the respective connections. When a computer goes to sleep, it will turn off any Ethernet and Wi-Fi adapters connected to the computer. This means that when in sleep mode, the computer cannot be accessed by a network connection. A hacker needs an active network connection to your computer to be able to access it. A computer that is in sleep mode is just as protected from hackers as a computer that has been turned off. A hacker can't send a wake-up command to the computer over a network connection if the computer doesn't have one.
The computer's hard drive stores all of its saved data, which hackers would go after if they are in your computer. While the lack of a network connection makes it impossible for a hacker to get into a sleeping computer, the hard drive has an additional layer of protection: It is turned off. Unless the computer is awoken from sleep state, the hard drive will remain inaccessible for hackers.
CPU and RAM
The system's CPU and RAM are the only two components still running when a computer is in sleep mode. The CPU doesn't contain any actual data, but the system RAM does. If a hacker were to hypothetically get into a sleeping computer without using a network connection, the RAM is the only active component that would have any accessible information. However, the state of the RAM's information would be limited in the hypothetical situation.