What are zombie computers and how can they affect network?

Zombie computers are any system

attached to a network that silently (unannounced to the user)

perform tasks on the network to reach a predetermined goal. A

computer system can become a zombie computer by being infected via

a network transferable source such as via email, or via a local

source delivered from a flash drive or other external source. It is

most common for each zombie computer to be performing a small

portion of the larger goal, and be part of a larger group of zombie

computers that are all working together for the same purpose. This

way, if one zombie computer is brought offline, the goal can still

be reached. It also ensures that each infected system is not

diverting a great deal of resources to the zombie process, which

helps to ensure the zombie node is not detected and repaired.

Network consequences are dependent

on what the task is that the zombie collective is working on, and

how many zombie nodes are contributing vs the scale of the network

they sit on. For example, if 10 systems on a network of 10,000

systems are infected, the likelihood of the network being bogged

down by the zombie traffic is minimal. However, it also depends on

whether the goal the zombie collective is trying to achieve is

targeting the local network they are on, or something outside the

network on the internet, as 10 computers working to overload a

local server, may achieve some results, while 10 computers trying

to overload google for instance would have little effect.