Apple cautioned allowing third-party apps to be sideloaded onto its devices would put all users at risk and could lead to malware attacks at unprecedented scale, as regulators continue to probe the tech giant’s policies.

In a lengthy privacy position document filled with detailed worse-case scenarios illustrating ways users could be scammed, Apple warned against the danger of downloading apps from websites and app stores it had not vetted.

“By providing additional distribution channels, changing the threat model and widening the universe of potential attacks, sideloading on iPhone would put all users at risk, even those who make a deliberate effort to protect themselves by only downloading apps through the App Store.”

It noted submitting to calls to change in its policies to allow apps to be sourced elsewhere would “spur a flood of new investment into attacks on iPhone”.

The company also detailed the security policies currently in place to vet applications provided through its official channel, outlined its general privacy policies and claimed to have rejected or removed almost a million “problematic” apps from its store during 2020.

Apple’s comments on sideloading apps come as a number of regulators are in the process of investigating the company for a range of potential competition issues, which includes access to apps on its devices and associated policies.