As digitization continues, modern software-defined infrastructures that optimize the use of existing hardware resources have gained importance. Cloud computing is an example of this shift, as it makes hardware resources available to developers and service providers, preventing over-provisioning and wasting resources. However, this reliance on virtualization and software deployments has left these infrastructures exposed to various software attacks, requiring robust security measures. Critical security and reliability requirements of software infrastructures are analyzed and discussed, with a focus on defending against software attacks. To mitigate such threats, technologies such as Trusted Execution Environment and Trusted Platform Module are widely used. The latter enables defense techniques such as Remote Attestation to verify hardware and software.