Which of the following is NOT a category of a PHA?

Jailbreaking is a process that removes software restrictions imposed by the operating system manufacturer, allowing users to gain root access to the device. While it can compromise device security, it is not categorized as a Potentially Harmful Application (PHA) by Android. PHAs are typically malicious software designed to harm the user, device, or data. Backdoors are PHAs that allow unauthorized remote access. Hostile downloaders are PHAs that download other malicious software without user consent. Denial of Service (DoS) attacks, while often executed by malware, refer to an attack type that makes a machine or network resource unavailable to its intended users, rather than a category of application itself.