Google has removed two adblock extensions from the Chrome Web Store. The extensions blocked ads but also secretly made money from affiliate programs by placing cookies.
The extensions are AdBlock from ‘AdBlock, Inc’ with over 800,000 users and uBlock from ‘Charlie Lee’ with 850,000 users. In fact, these were clones of popular extensions, writes AdGuard, which notes that there are many more clones in the Chrome Web Store.
The extensions are based on the original AdBlock code and therefore block ads, but after about 55 hours they also place affiliate cookies in browsers. These ensure that when users make purchases on websites, the creator of the extension receives a certain commission. This form of fraud is also called cookie stuffing or cookie dropping. The extensions hooked up to affiliate programs from TeamViewer, Microsoft, LinkedIn, AliExpress and Booking.com.
Interestingly, according to AdGuard, the extensions had certain protection methods against detection: as soon as a user opened a developer console in his browser, the malicious activities stopped. Google has removed the two extensions from the Chrome Web Store.