Just a few days ago The news was released that Google has started with the approval process of Chrome auto-lock mode, in which it puts a heavy load on the CPU or load of too much traffic. When this happens if certain limits are exceeded, advertising iframes that consume too much resources will be automatically disabled from the web browser.
Given this initiative it is observed that some types of advertising, due to inefficient code implementation or deliberate parasitic activity, create a large load of resources on the user's system, which slow down the loading of the main content, reduce battery life and consume traffic with unlimited mobile rates.
Of the typical examples of ad units to be blocked, the insertions of ads with cryptocurrency mining code, big image processors uncompressed, JavaScript video decoders, or scripts that intensively process timer events (for example, third-party channel attacks).
In its statement Google comments:
Summary
Chrome will download ad iframes that use a large amount of CPU or network bandwidth. Iframes are heuristically tagged as ads by AdTagging. The limits for this intervention are defined in the explainer.
Motivation
A small fraction of advertisements on the web use a large amount of system resources. These low-performing ads (whether intentional or not) harm the user's browsing experience by slowing down pages, draining the device's battery, and consuming mobile data (for those without unlimited plans).
In these egregious cases, the browser may download the offensive ads to protect the resources of the individual's device. This is a strong intervention that is intended to safeguard user resources with low risk because downloading an ad is unlikely to cause the loss of functionality of the main content on the page.
Common examples of these ads include:
- cryptominers
- Ads that upload large uncompressed image files
- Ads that use JavaScript to decode video files
Risks
Interoperability and compatibility
There is some interoperability risk here. There is currently no unified way for browsers to identify ads.
Other browsers address some of the motivating use cases through other user protections. Edge tackles crypto miners through tracking protection. Firefox also offers a subscription mechanism that stops known crypto mining scripts.
Basically it is proposed to block the code if this consumed more than 60 seconds of the total processor time on the main thread or 15 seconds in a 30 second interval (consumes 50% of resources for more than 30 seconds).
The user agent will block all those ads that use a large amount of network bandwidth or CPU usage.
Blocking It will also be triggered when the ad unit loads more than 4MB of data over the network.
To exclude the use of blocking as a signal of attacks on third-party channels, which can be used to judge CPU power, it is proposed to add small random fluctuations to the threshold values ​​and blocking response.
Only ads that the user did not interact with will be loaded and will be replaced with a warning about the crash.
The determination of the relationship between iframes and advertising is done automatically using the existing AdTagging mechanism.
The thresholds are selected to pass the activity of 99,9% of the analyzed ad units. Further, the proposed blocking mechanism is expected to reduce traffic of ad units by 12,8% and will reduce the load on the CPU by 16,1%.
This intervention will be independent of the platform (desktop / mobile device) so that the authors can easily know if their ad would be subject to intervention or not. Thresholds may need to be changed as the web ecosystem and common device profiles evolve.