Check Point researchers recently spotted a flaw in one of Android’s security mechanisms. This flaw exposes Android users to several types of attacks, including ransomware, banking malware and adware.
Check Point researchers say they have spotted a flaw in one of Android’s security mechanisms. Based on Google’s policy which grants extensive permissions to apps installed directly from Google Play, this flaw exposes Android users to several types of attacks, including ransomware, banking malware and adware. Check Point reported this flaw to Google, which responded that this issue is already being dealt with in the upcoming version of Android, currently dubbed “Android O”.
In Android version 6.0.0, dubbed “Marshmallow”, Google introduced a new permission model for apps. The new model consists of several groups of permissions, with permissions considered as “dangerous” granted only during runtime. This means that during the first time an app tries to access a “dangerous” resource, the user is required to approve the necessary permission.
In addition to the “dangerous” permissions, another category exists, which contains a single permission – SYSTEM_ALERT_WINDOW. Unlike the other permissions, to grant it, the user must go through several menus (Settings -> Apps -> Draw over other apps) and manually allow an app to use it.
The reason SYSTEM_ALERT_WINDOW is unique is the extensive capability it withholds, by enabling an app to display over any other app without notifying the user. This entails a significant potential for several malicious techniques, such as displaying fraudulent ads, phishing scams, click-jacking, and overlay windows, which are common with banking Trojans. It can also be used by ransomware to create a persistent on-top screen that will prevent non-technical users from accessing their devices. According to our findings, 74% of ransomware, 57% of adware, and 14% of banker malware abuse this permission as part of their operation. This is clearly not a minor threat, but an actual tactic used in the wild.
Since Google understood the problematic nature of this permission, and the apparent risks for user privacy it created the distinct process mentioned above to approve it. However, this soon caused problems, as this permission is also used by legitimate apps, such as Facebook, which requires it for its Messenger chat heads feature. Since most users won’t be able to approve the permission manually, such apps could be hurt by it.
As a temporary solution, Google applied a patch in Android version 6.0.1 that allows the Play Store app to grant run-time permissions, which are later used to grant SYSTEM_ALERT_WINDOW permission to apps installed from the app store. This means that a malicious app downloaded directly from the app store will be automatically granted this dangerous permission.
Based on Check Point research, nearly 45% of the applications using the SYSTEM_ALERT_WINDOW permission are apps from Google Play. With the granting of SYSTEM_ALERT_WINDOW permission to apps installed from the app store, Google effectively bypasses the security mechanism introduced in the previous version. Google relies heavily on “Bouncer”, which scans apps uploaded to Google Play, to keep harmful apps out of it. Unfortunately, malicious apps successfully infiltrate Google Play time after time. FalseGuide and Skinner discovered on Google Play are two recent examples.
Google is working on a fix
After Check Point reported this flaw, Google responded it has already set plans to protect users against this threat in the upcoming version “Android O”. This will be done by creating a new restrictive permission called TYPE_APPLICATION_OVERLAY, which blocks windows from being positioned above any critical system windows, allowing users to access settings and block an app from displaying alert windows.
How to stay protected in the meantime?
· Beware of fishy apps
Users should always beware of malicious apps, even when downloading from Google Play. Look for the comments left by other users, and grant only permissions which have relevant context for the app’s purpose.
· Implement advanced security measures
Just as you protect your PC with dedicated security solutions, you should also make sure to protect your mobile device using a protective solution capable of identifying and blocking known and unknown malware.
Cons exploit Telegram ICO
Kaspersky Lab researchers have uncovered dozens of highly convincing fake websites claiming to be investment sites for an initial coin offering (ICO) by the Telegram messaging service. Many of these websites appear to belong to the same group. In one case alone, tens of thousands of US dollars’ worth of cryptocurrency were stolen from victims believing they were investing in ‘Grams’, Telegram’s rumoured new currency. Telegram has not officially confirmed an ICO and has warned people about fraudulent investor sites.
In late 2017, stories started to circulate that the Telegram messaging service was launching an initial coin offering (ICO) to finance a blockchain platform based on its TON (Telegram Open Network) technology. Unverified technical documentation was posted online, but there appears to have been no confirmation from Telegram itself. The resulting confusion seems to have allowed fraudsters to capitalise on investor interest by creating fake sites and stealing vast sums of money.
Kaspersky Lab researchers have discovered dozens of such sites, possibly belonging to the same group, claiming to sell tokens for ‘Grams’ and inviting investors to pay with cryptocurrencies including Bitcoin, Ethereum, lice litecoin, dash and Bitcoin dash. A record of transactions on one site revealed that the scammers were able to steal at least $35,000 US dollars’ worth of Ethereum from investors.
The researchers found that some of the websites were so convincing that even after Telegram and others began to issue warnings, they were still able to recruit potential investors. Most use a secure connection, require registration and generate a unique online wallet for each new victim, making it harder to track the money.
Judging by the content of the fake websites, it appears they may have common ownership. For example, several have the exactly the same ‘Our Team’ section.
“ICOs are a fairly risky investment and many people don’t yet fully understand how they work, so it is not surprising that high quality fake websites, with seemingly reassuring features such as a secure connection and registration are successful at luring people in. People wishing to invest in an ICO would do well to check with the company behind it and make sure they know exactly who they are giving their money to, or they may never see it again,” said Nadezhda Demidova, Lead Web-Content Analyst, Kaspersky Lab.
Kaspersky Lab offers the following advice for users considering investing in an ICO:
- Check for warning signs: for example, some of the fake Telegram ICO websites had the same wrong image next to the name of Telegram’s Chief Product Officer.
- Do your homework: always check with the brand’s official site to verify the legitimacy of the investment site and, if necessary contact the company’s ICO teams before investing any money or currency.
- Use reliable security solutions such as Kaspersky Internet Security and Kaspersky Internet Security for Android, which will warn you if you try to visit fake internet pages.
Crouching Yeti strikes
Kaspersky Lab has uncovered infrastructure used by the Russian-speaking APT group Crouching Yeti, also known as Energetic Bear, which includes compromised servers across the world.
According to the research, numerous servers in different countries were hit since 2016, sometimes in order to gain access to other resources. Others, including those hosting Russian websites, were used as watering holes.
Crouching Yeti is a Russian-speaking advanced persistent threat (APT) group that Kaspersky Lab has been tracking since 2010. It is best known for targeting industrial sectors around the world, with a primary focus on energy facilities, for the main purpose of stealing valuable data from victim systems. One of the techniques the group has been widely using is through watering hole attacks: the attackers injected websites with a link redirecting visitors to a malicious server.
Recently Kaspersky Lab has discovered a number of servers, compromised by the group, belonging to different organisations based in Russia, the U.S., Turkey and European countries, and not limited to industrial companies. According to researchers, they were hit in 2016 and 2017 with different purposes. Thus, besides watering hole, in some cases they were used as intermediaries to conduct attacks on other resources.
In the process of analysing infected servers, researchers identified numerous websites and servers used by organisations in Russia, U.S., Europe, Asia and Latin America that the attackers had scanned with various tools, possibly to find a server that could be used to establish a foothold for hosting the attackers’ tools and to subsequently develop an attack. Some of the sites scanned may have been of interest to the attackers as candidates for waterhole. The range of websites and servers that captured the attention of the intruders is extensive. Kaspersky Lab researchers found that the attackers had scanned numerous websites of different types, including online stores and services, public organisations, NGOs, manufacturing, etc.
Also, experts found that the group used publicly available malicious tools, designed for analyzing servers, and for seeking out and collecting information. In addition, a modified sshd file with a preinstalled backdoor was discovered. This was used to replace the original file and could be authorised with a ‘master password’.
“Crouching Yeti is a notorious Russian-speaking group that has been active for many years and is still successfully targeting industrial organisations through watering hole attacks, among other techniques. Our findings show that the group compromised servers not only for establishing watering holes, but also for further scanning, and they actively used open-sourced tools that made it much harder to identify them afterwards,” said Vladimir Dashchenko, Head of Vulnerability Research Group at Kaspersky Lab ICS CERT.
“The group’s activities, such as initial data collection, the theft of authentication data, and the scanning of resources, are used to launch further attacks. The diversity of infected servers and scanned resources suggests the group may operate in the interests of the third parties,” he added.
Kaspersky Lab recommends that organisations implement a comprehensive framework against advanced threats comprising of dedicated security solutions for targeted attack detection and incident response, along with expert services and threat intelligence. As a part of Kaspersky Threat Management and Defense, our anti-targeted attack platform detects an attack at early stages by analysing suspicious network activity, while Kaspersky EDR brings improved endpoint visibility, investigation capabilities and response automation. These are enhanced with global threat intelligence and Kaspersky Lab’s expert services with specialisation in threat hunting and incident response.
More details on this recent Crouching Yeti activity can be found on the Kaspersky Lab ICS CERT website.