What could be used to launch a denial of service attack on a provider?

1. A large attack needs many machines behind it. 2. Compromised machines can be marshalled together. 3. Botnets could be used to launch a denial of service attack against a cloud provider's infrastructure. 4. So the answer is botnets. _Source: NIST SP 800-144, 'Guidelines on Security and Privacy in Public Cloud Computing'_