AccessDefault is classified as a PUP (Potentially Unwanted Program) due to the underhanded tactics it uses to spread itself. Its main targets are Mac users. Instead of waiting for users to download and install it willingly, AccessDefault sneaks its installation process inside a fake installer/updater or is packaged alongside another software product. Once inside the user's device, the application proceeds to initiate its two core functionalities - that of adware and a browser hijacker.
As part of the adware activities, users will be subjected to an intrusive advertising campaign. Numerous dubious advertisements would start appearing on the device, leading to a significantly diminished user experience. The browser hijacker, on the other hand, will take control over the Web browser. It would then promote a sponsored address, usually a fake search engine, by modifying the homepage, new tab page, and the default search engine. Users should approach both the ads generated by AccessDefault and the results listed by the fake search engine with caution.
Furthermore, nearly all PUPs possess data-harvesting capabilities. Most are content with monitoring and exfiltrating the user's browsing habits such as visited websites and conducted searches. However, some PUPs also try to access sensitive data that has been saved into the browser. This could include payment or banking details as well as credit/debit card numbers.