A botnet is a collection of virus-infected computers that, without the owner's knowledge, can be commandeered and used by another individual to carry out online attacks against companies or internet networks.
On Saturday, the websites of several media companies in Sweden were inaccessible after being overwhelmed by a flood of online traffic.
The agency believes several of the sites were specifically targeted by two separate attacks but that some sites were take offline simply because they used the same infrastructure and were therefore overloaded at the same time.
It's still unclear who was behind the attack though Swedish police are investigating it.
On Wednesday afternoon, Home Affairs Minister Anders Ygeman and Democracy Minister Alice Bah Kuhnke met with several media companies to discuss the situation.