To tackle this question we will begin with a very basic discussion on output devices. We all know that our computer’s monitor and printer are output devices. To be precise, an output device of a computer is a hardware which is dedicated to communicate the end results of an activity or processing, performed by its CPU, to the end user. It is a means to display the information processed by the computer to humans in a format that can be read and understood by them. This output information could be in the form of text, images and graphics, sounds as well as videos. Therefore, speakers, microphones, projector, and plotter etc., apart from printer and monitor, come under the category of output devices.
A standalone output device does not inherently have a software in it. Therefore, it is less likely that it can infect your computer. For example, if we talk about monitor, printer, microphone, or a projector, being connected with an infected computer, it will obviously not carry the infected program or virus to another computer. Though, any infection in driver program in a PC may cause these peripheral devices to function abruptly on that particular system, but it will not make them carry the infection to another system.
However, hackers leave no stone unturned to devise newer threats to cause havoc in the IT world. These cyber attackers have now been successful in bringing up a rootkit to infect the driver programs of printer. Furthermore, certain worms are capable of infecting printers connected with a network and causing them to re-infect the computers on the same network. However, the same printer might not infect computers on a different network if connected with them, as one would need to install the driver program independently on that network. Therefore, we shall conclude by saying that an output device is not capable of carrying a computer virus, however it might function abruptly if the supporting driver program has been compromised by a malicious code. It is advisable to have one’s antivirus updated on a regular basis to avoid such troubles.