Apple on Wednesday ramped up its criticism of EU draft rules that would force it to allow users to install software from outside its App Store, citing the risks posed by cybercriminals and malware.

The iPhone maker has been a fierce critic of EU antitrust chief Margrethe Vestager’s proposed rules, which were announced last year in a bid to rein in Apple, Amazon, Facebook and Alphabet unit Google. Building on CEO Tim Cook’s comments in June about the risks to privacy and security of iPhones, Apple on Wednesday published an analysis on the threats of so-called side-loading.

“If Apple were forced to support sideloading, more harmful apps would reach users because it would be easier for cybercriminals to target them – even if sideloading were limited to third-party app stores only.”

It warned of malicious apps migrating to third-party stores and infecting consumer devices, while users would have less control over downloaded apps.

The study cited figures from cybersecurity services provider Kaspersky Lab which showed nearly six million attacks per month affected Android mobile devices.

Apple also took a swipe at digital advertisers with whom it is at loggerheads over its new privacy controls designed to limit them from tracking iPhone users.

According to the report, large companies that rely on digital advertising allege that they have lost revenue due to these privacy features, and may therefore have an incentive to distribute their apps via sideloading specifically to bypass these protections.