Breakdown of ¿Está infectada la red de la empresa?
de
from / of
estar
to be (location/state)
la empresa
company
la red
network
Questions & Answers about ¿Está infectada la red de la empresa?
Why does the past participle infectada end in '-a' here?
Because it is part of the state passive (estar + past participle), which describes the resulting state of something. In this structure, the past participle acts like an adjective and must agree in gender and number with the subject. The subject is la red (the network), which is feminine and singular, so infectado becomes infectada.
Could I use es instead of está in this sentence?
Not for this meaning. Using estar (the state passive) focuses on the result or current condition of the network. If you used ser (the action passive, as in ¿Es infectada la red?), you would be asking if the network is actively in the process of being infected by someone or something right now, which sounds very unnatural.
Why is the subject la red de la empresa at the very end of the question?
In Spanish questions, it is extremely common to invert the word order by placing the entire verb phrase (está infectada) before the subject (la red de la empresa). You could also say ¿La red de la empresa está infectada?, but keeping the verb and participle together at the beginning flows very naturally.
Does red only refer to digital networks?