Comment by lcnPylGDnU4H9OF

> The report is highly sensationalist in the "zero-click" aspect. It details to some degree the aspects of distribution and C&C but goes very vague the main point - what was the mechanism that activated that zero malware in a zero-click fashion.

It read to me like it was assumed to be using OS/browser/application-level exploits to get further access to target devices. I suspect the CitizenLab report is light on details in particular because they don't actually know them:

> In most cases, the user who sees the ad is not selected for targeting, and the server will not return any JavaScript to be executed.

> A large number of ads placed by Discover-Tech contain a script tag pointing back to what the company refers to as a “NOAS server” (also called a “getAd server”). This tag causes the ad, when rendered, to connect back to Discover-Tech, submit advertising identifiers for the user (either a cookie ID or a mobile ad ID), and automatically execute any JavaScript code returned. The NOAS server decides, apparently based on a combination of the source IP address and the advertising identifiers, whether the target is eligible to receive any JavaScript. If so, then code is returned. If not, a 0-byte response is returned. The NOAS server is a key part of Discover-Tech’s strategy, allowing Discover-Tech to avoid directly sharing malicious code, or even pointers to malicious code, with the companies who serve and display the ads.