Kategori : ELECTRICITY ENERGY NEWS, ENERGY AGENDA NEWS, GREEN TECHNOLOGY AND INFORMATION NEWS - Tarih : 25 July 2021
We hope you already know that you shouldn’t click on just any URLs. You might be sent one in a message; somebody might insert one under a social media post or you could be provided with one on basically any website. Users or websites providing these links might use URL shortener services. These are used to shorten long URLs, hide original domain names, view analytics about the devices of visitors, or in some cases even monetize their clicks.
Monetization means that when someone clicks on such a link, an advertisement, such as the examples in Figure 1, will be displayed that will generate revenue for the person who generated the shortened URL. The problem is that some of these link shortener services use aggressive advertising techniques such as scareware ads: informing users their devices are infected with dangerous malware, directing users to download dodgy apps from the Google Play store or to participate in shady surveys, delivering adult 
content, offering to start premium SMS service subscriptions, enabling browser notifications, and making dubious offers to win prizes.
We’ve even seen link shortener services pushing “calendar” files to iOS devices and distributing Android malware – indeed, we discovered one piece of malware we named Android/FakeAdBlocker, which downloads and executes additional payloads (such as banking trojans, SMS trojans, and aggressive adware) received from its C&C server.
Below we describe the iOS calendar-event-creating downloads and how to recover from them, before spending most of the blogpost on a detailed analysis of the distribution of Android/FakeAdBlocker and, based on our telemetry, its alarming number of detections. This analysis is mainly focused on the functionality of the adware payload and, since it can create spam calendar events, we have included a brief guide detailing how to automatically remove them and uninstall Android/FakeAdBlocker from compromised devices.
Distribution
Content displayed to the victim from monetized link shorteners can differ based on the running operating system. For instance, if a victim clicked on the same link on a Windows device and on a mobile device, a different website would be displayed on each device. Besides websites, they could also offer an iOS device user to download an ICS calendar file, or an Android device user to download an Android app. Figure 2 outlines options we have seen in the campaign analyzed here.
While some advertisements and Android applications served by these monetized shortened links are legitimate, we observed that the majority lead to shady or unwanted behavior.
iOS targets
On iOS devices, besides flooding victims with unwanted ads, these websites can create events in victims’ calendars by automatically downloading an ICS file. Victims must first tap the subscribe button to spam their calendars with these events. However, the calendar name “Click OK To Continue (sic)” is not revealing the true content of those calendar events and only misleads the victims into tapping the Subscribe and Done button.
These calendar events falsely inform victims that their devices are infected with malware, hoping to induce victims to click on the embedded links, which lead to more scareware advertisements.
More Details: https://www.welivesecurity.com/2021/07/20/url-shortener-services-android-malware-banking-sms-trojans/
