We’ve just launched a new version of the Site Status Tool that provides simpler, clearer results and is better designed for the primary users of the page: people who are visiting the tool from a Safe Browsing warning they’ve received, or doing casual research on Google’s malware and phishing detection. The tool now features a cleaner UI, easier-to-interpret language, and more precise results. We’ve also moved some of the more technical data on associated ASes (autonomous systems) over to the malware dashboard section of the report.
While the interface has been streamlined, additional diagnostic information is not gone: researchers who wish to find more details can drill-down elsewhere in Safe Browsing’s Transparency Report, while site-owners can find additional diagnostic information in Search Console. One of the goals of the Transparency Report is to shed light on complex policy and security issues, so, we hope the design adjustments will indeed provide our users with additional clarity.
In order to secure some of the details of our detection, we often send a batch of warnings to groups of at-risk users at the same time, and not necessarily in real-time. Additionally, we never indicate which government-backed attackers we think are responsible for the attempts; different users may be targeted by different attackers.
Security has always been a top priority for us. Robust, automated protections help prevent scammers from signing into your Google account, Gmail always uses an encrypted connection when you receive or send email, we filter more than 99.9% of spam — a common source of phishing messages — from Gmail, and we show users when messages are from an unverified or unencrypted source.
An extremely small fraction of users will ever see one of these warnings, but if you receive this warning from us, it's important to take action on it. You can always take a two-minute Security Checkup, and for maximum protection from phishing, enable two-step verification with a Security Key.
Google works hard to protect users across a variety of devices and environments. Part of this work involves defending users against Potentially Harmful Applications (PHAs), an effort that gives us the opportunity to observe various types of threats targeting our ecosystem. For example, our security teams recently discovered and defended users of our ads and Android systems against a new PHA family we've named Chamois.
Chamois is an Android PHA family capable of:
Generating invalid traffic through ad pop ups having deceptive graphics inside the ad
Performing artificial app promotion by automatically installing apps in the background
We detected Chamois during a routine ad traffic quality evaluation. We analyzed malicious apps based on Chamois, and found that they employed several methods to avoid detection and tried to trick users into clicking ads by displaying deceptive graphics. This sometimes resulted in downloading of other apps that commit SMS fraud. So we blocked the Chamois app family using Verify Apps and also kicked out bad actors who were trying to game our ad systems.
Our previous experience with ad fraud apps like this one enabled our teams to swiftly take action to protect both our advertisers and Android users. Because the malicious app didn't appear in the device's app list, most users wouldn't have seen or known to uninstall the unwanted app. This is why Google's Verify Apps is so valuable, as it helps users discover PHAs and delete them.
Under Chamois's hood
Chamois was one of the largest PHA families seen on Android to date and distributed through multiple channels. To the best of our knowledge Google is the first to publicly identify and track Chamois.
Chamois had a number of features that made it unusual, including:
Multi-staged payload: Its code is executed in 4 distinct stages using different file formats, as outlined in this diagram.
This multi-stage process makes it more complicated to immediately identify apps in this family as a PHA because the layers have to be peeled first to reach the malicious part. However, Google's pipelines weren't tricked as they are designed to tackle these scenarios properly.
Self-protection: Chamois tried to evade detection using obfuscation and anti-analysis techniques, but our systems were able to counter them and detect the apps accordingly.
Custom encrypted storage: The family uses a custom, encrypted file storage for its configuration files and additional code that required deeper analysis to understand the PHA.
Size: Our security teams sifted through more than 100K lines of sophisticated code written by seemingly professional developers. Due to the sheer size of the APK, it took some time to understand Chamois in detail.
Google's approach to fighting PHAs
Verify Apps protects users from known PHAs by warning them when they are downloading an app that is determined to be a PHA, and it also enables users to uninstall the app if it has already been installed. Additionally, Verify Apps monitors the state of the Android ecosystem for anomalies and investigates the ones that it finds. It also helps finding unknown PHAs through behavior analysis on devices. For example, many apps downloaded by Chamois were highly ranked by the DOI scorer. We have implemented rules in Verify Apps to protect users against Chamois.
Google continues to significantly invest in its counter-abuse technologies for Android and its ad systems, and we're proud of the work that many teams do behind the scenes to fight PHAs like Chamois.
We hope this summary provides insight into the growing complexity of Android botnets. To learn more about Google's anti-PHA efforts and further ameliorate the risks they pose to users, devices, and ad systems, keep an eye open for the upcoming "Android Security 2016 Year In Review" report.
Globally, we’ve noticed other interesting trends. Russia has consistently occupied a position in the top 10 every year the last 7 years. We have noticed a 3X increase in reports from Asia, making up 70% of the Android Security Rewards for 2016. We have seen increases in the number of researchers reporting valid bugs from Germany (27%), and France (44%). France broke into our top 5 countries in 2016 for the first time.
In 2016, we delivered technical talks along with educational trainings to an audience of enthusiastic security professionals in Goa at the Nullcon security conference. This year, we continue our investment at Nullcon to deliver content focused on the growing group of bug hunters we see in India. If you are attending Nullcon please stop by and say “Hello”!
As part of this next step towards reducing macOS-specific malware and unwanted software, Safe Browsing is focusing on two common abuses of browsing experiences: unwanted ad injection, and manipulation of Chrome user settings, specifically the start page, home page, and default search engine. Users deserve full control of their browsing experience and Unwanted Software Policy violations hurt that experience.
The recently released Chrome Settings API for Mac gives developers the tools to make sure users stay in control of their Chrome settings. From here on, the Settings Overrides API will be the only approved path for making changes to Chrome settings on Mac OSX, like it currently is on Windows. Also, developers should know that only extensions hosted in the Chrome Web Store are allowed to make changes to Chrome settings.
Starting March 31 2017, Chrome and Safe Browsing will warn users about software that attempts to modify Chrome settings without using the API.
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