A team of malware authors is playing a cat and mouse game with Google. The game goes like this: they upload their malware, Google Play quickly takes it down, they upload a new mutation and Google takes it down. Current status of the game: the malware is back on Google Play. So far, the malicious apps have infected hundreds of thousands of innocent victims.
In April, we discovered porn clicker malware on Google Play posing as the popular Dubsmash app.
Two days ago, we reported that a mutation of the porn clicker malware, created by a Turkish group of malware authors, made its way back onto Google Play, but have since been removed from the Play Store.
Once the apps were downloaded they did not do anything significant when opened by the user, they just showed a static image. However, once the unsuspecting victim opened his/her browser or other apps, the app began to run in the background and redirect the user to porn sites. Users may not have necessarily understood where these porn redirects were coming from, since it was only possible to stop them from happening once the app was killed. Fellow security researchers at Eset reported that more apps with this mutation were on Google Play earlier this week. Eset also reported that the original form of the malware was uploaded to Google Play multiple times in May. Our findings combined with that from Eset, prove that these malware authors are extremely persistent and determined to make Google Play a permanent residency for their malware.
I’ll be back…
Malware Writers Can’t Keep Their Hands Off Porn
In April, we reported on a porn clicker app that slipped into Google Play posing as the popular Dubsmash app. It seems that this malware has mutated and once again had a short-lived career on Google Play, this time hidden in various “gaming” apps.
For your viewing pleasure
The original form of this porn clicker ran completely hidden in the background, meaning victims did not even notice that anything was happening. This time, however, the authors made the porn a bit more visible to their victims.
The new mutation appeared on Google Play on July 14th and was included in five games, each of which was downloaded by 5,000-10,000 users. Fortunately, Google reacted quickly and has already taken down the games from the Play Store.
Once the app was downloaded, it did not really seem to do anything significant when opened by the user. However, once the unsuspecting victim opened his/her browser or other apps, the app began to run in the background and redirect the user to porn sites. Users may not have necessarily understood where these porn redirects were coming from, since it was only possible to stop them from happening once the app was killed.
Mid January we informed you of a data-stealing piece of Android malware called Fobus. Back then Fobus mainly targeted our users in Eastern Europe and Russia. Now, Fobus is also targeting our users in the USA, United Kingdom, Germany, Spain and other countries around the world.
Fobus can cost its unaware victims a lot of money, because it sends premium SMS, makes calls without the victims’ knowledge and can steal private information. More concerning is that Fobus also includes hidden features that can remove critical device protections. The app tricks users into granting it full control of the device and that is when this nasty piece of malware really begins to do its work. You can find some more technical details and analysis of Fobus in our previous blog post from January.
Today, we decided to look back and check on some of the data we gathered from Fobus during the last six months. We weren’t surprised to find out that this malware family is still active and spreading, infecting unaware visitors of unofficial Android app stores and malicious websites.
The interesting part of this malware is the use of server-side polymorphism, which we suspected was being used back in January but could not confirm. We have now confirmed that server-side polymorphism is being used by analyzing some of the samples in our database. Most of these have not only randomly-generated package names, but it also seems that they have randomly-generated signing certificates.
The Avast Threat Report provides an overview of global threat activity.
Avast malware researchers and Avast customers work 24/7 to protect each other.
Avast protects 230 million people worldwide in more than 186 different countries — we are present in more countries than McDonalds and protect more people than any other antivirus security provider. We stream 250 micro updates a day that protect our users from attacks. This is made possible by the 230 million devices we protect that simultaneously act as de facto sensors. These sensors provide us with information about suspicious files to help detect and neutralize threats as soon as they appear. Once we identify a suspicious file on a single device, it is reported back to the Avast servers and all Avast users around the world are immediately protected. This is called our Community IQ – it not only lets us better protect our users but also gives us valuable insights into the current security landscape.
Most Internet users are familiar with this problem all too well: After downloading a video player, Java, Flash updates or other software, the browser has suddenly changed. New buttons and icons in all colors and sizes along with an URL entry bar take up valuable real estate on your browser. The browser runs noticeably slower – and the results look different. Most annoying is that the advertising becomes more prominent.
Over the past two years, Avast Browser Cleanup has identified more than 60 million different browser add-ons which are often bundled with other free software, such as video players, Java and Flash updates. These toolbars typically occupy the horizontal space below a user’s browser and can include buttons, icons, and menus. Despite removing and re-installing a browser, toolbars will often remain, which is a behavior similar to malware.
Earlier this year, we told you about the return of CryptoWall, malware that encrypts certain files in your computer and, once activated, demands a fine around $500 as a ransom to provide the decryption key. These kinds of financial fraud schemes target both individuals and businesses, are usually very successful and have a significant impact on victims. The problem begins when the victim clicks on an infected advertisement, email, or attachment, or visits an infected website.
Recently, a click fraud botnet with ties to CryptoWall has been discovered. The malware, nicknamed ‘RuthlessTreeMafia‘, has been being used to distribute CryptoWall ransomware. What first appears as an attempt to redirect user traffic to a search engine quickly mutates into an alarming threat as infected systems begin to download CryptoWall and system files and data become encrypted, rendering them useless by their owners. Click fraud and ransomware are two types of crimeware that are usually quite different from one another and typically don’t have many opportunities to join forces; therefore, the result of this unlikely yet powerful collaboration can be detrimental to its victims.
The Avast bi weekly wrap-up is a quick summary of what was on the Avast blog for the last two weeks.
Most everyone knows their PC needs antivirus protection, but they don’t think about their smartphone. These days smartphones are just about as powerful and have as much or more personal information as our desktop PC at home. We answer the question do Android devices really need protection?
The answer is a resounding YES. The Avast Virus Lab gives us an example from a trusted download source, Google Play: A porn clicker app slipped into Google Play imitating the popular Dubsmash app. If we cannot completely rely on trusted app stores to weed out nasty apps, then it’s time to add an extra layer of security.
Once you decide that you do want to protect your Android device, you can be confident in Avast Mobile Security, Avast’s free security app available on Google Play. A survey by AV -Comparatives said that Avast was the #1 choice for mobile security in the entire world. No need to wait any longer to protect your smartphone or tablet.
One of the challenges with using a smartphone for so many activities, is that the battery gives out before we do. Our new free app Avast Battery Saver raises the bar with new Wi-Fi based smart profiles that can increase battery life by an average of 7 hours.
Avast Battery Saver has only been available for a month or so but already 200,000 customers have downloaded it from the Google Play Store. For Earth Day we highlighted battery saver users for their positive impact on the environment. Who knew that Avast Battery Saver would be so green? A cool infographic shows just how much they saved - not only from their own battery - but in energy costs too. Now Earth Day can be everyday!
Small and medium-sized businesses (SMBs) run the risk of data breaches just like there Enterprise cousins. Luke Walling, the General Manager of Avast for Business, explains that the biggest threat to SMBs is not actually hackers sitting somewhere far away. The biggest threat to your SMB could be sitting in your office!
Speaking of Avast for Business, our new disruptive free security offering for SMBs has 75,000 new customers in just 2 months. If you have a start-up, a small business, if you work in a school or non-profit organization, then it’s time to stop paying for security protection.
Our researchers are constantly surprised by the creativity of malware authors. Recently, they found a new way cybercrooks trick people in giving up their banking information. It’s a crafty combination of spam email, social engineering, and a macro code embedded in an innocent looking Word document.
Most people have security protection on their computers. That’s great when there are things like the banking malware we wrote about. With all that great protection why is it that they don’t trust the warnings? The Avast Virus Lab explored why some people would rather be right than believe a malware warning.
The most popular mobile security product in the world is Avast Mobile Security.
In their annual IT Security Survey, AV – Comparatives asked, Which mobile anti-malware security solution do you primarily use on your smartphone?
Avast took 1st or 2nd place on four continents: Europe, North America, Asia, and South/Central America.
How great is the risk of infection on an Android smartphone?
The risk of your Android smartphone becoming infected depends on several factors. In the US and Europe most people use official stores such as Google Play for installing apps. The risk is much lower than in many Asian countries, especially China, where app stores are not subject to stricter controls. Because of these unofficial app stores, along with numerous rooted phones, the chance of installing a dangerous app is highly increased.
In Asia, the smartphone is often used as an alternative to the PC. People frequently use it for online banking which make them vulnerable to Zeus Trojan malware. Zeus is commonly delivered via a link or an attachment in a phishing message or through a text message via WhatsApp, SMS, or Twitter. This threat will similarly increase in Europe and the US as banking apps get more popular.
An ounce of prevention is worth a pound of cure
The Avast Virus Lab has more than one million samples of mobile malware in its database, and reports that 2,850 new mobile threats are created every day by hackers. The threat situation can change quickly and dramatically so it is best to use preventative protection and install security software on your smartphone. At this point though, protecting important data in the event that your phone is lost or stolen is more critical than malware protection.
The AV-Comparatives survey says that Android users in North America protect their phones more than anywhere else in the world with 31 percent of respondents reporting they have protection. South America, Asia, and Europe are much lower at 17 percent.
Protect your Android smartphone and tablet with Avast Mobile Security and Avast Anti-Theft: Free from the Google Play store.
Everyone from celebrities like Lena Dunham to Hugh Jackman are using the (currently) seventh most popular app available on Google Play: Dubsmash. Dubsmash is an app with more than 10 million Google Play installations that lets users choose a sound, record a video to go along with the sound and send their dub to their friends or social media channels. Dubsmash is not only widely popular amongst teens and celebs, but the app has also caught the attention of malware authors.
Avast recently discovered “Dubsmash 2” (with the package name “com.table.hockes”) on Google Play – and no, it was not the bigger and better version of the original app. The app is a so called “porn clicker” and was installed 100,000-500,000 times from the Google Play Store. We contacted Google when we discovered the rogue app and it was removed from the Play Store shortly thereafter. Once the app was installed there was no evidence of an app named “Dubsmash 2” on the user’s device, instead the app installed an app icon named “Setting IS”. This is a common trick malware authors use to make it harder for the user to figure out which app is causing problems. This should also be the user’s first clue that something shady is going on. The “Settings IS” icon looked very similar to the actual Android Settings icon (see screenshot below).
The app’s mischievous activities could be triggered by two actions. The first possible way was by simply launching the “Settings IS” app and the second, which occurred only if the user had not yet launched the app, was via the BroadcastReceiver component within the app. BroadcastReceiver observed the device’s Internet connectivity and if the BroadcastReceiver noticed the device was connected to the Internet, the app’s true functions would be triggered.
If the “Settings IS” app was opened by the user, the Google Play Store would launch to the actual “Dubsmash” app download page.
Once activated, the app sent an HTTP GET request to an encrypted URL. If the request returned a string containing the character “1” two services would begin to work: MyService and Streaming. Using this method the author could also effectively turn off the start of the services remotely.
The second service, the Streaming service, was fairly similar in structure to the MyService component in that it also scheduled a task to run every 60 seconds. The main difference to MyService, is that users could notice the Service tasks did not run secretly in the background. The task would check for changes in the device’s IP address or date. If either of them had changed, a video would launch in the device’s YouTube app. The YouTube app needed to be installed on the device for this to function properly. The video address was also obtained from an encrypted URL.
After decrypting and further examining the URLs and the video from YouTube, the Avast Virus Lab came to the conclusion that the malware most likely originated from Turkey. The developer’s name listed on Google Play and YouTube hint to this.
We suspect the app developer used the porn clicker method for financial gain. Through clicks on multiple ads within the porn sites, the app developer probably received pay-per-click earnings from advertisers who thought he was displaying their ads on websites for people to actually see.
Despite being undesirable, but basically harmless to the user and less sophisticated than other malware families such as Fobus or Simplocker, this app shows that although there are safeguards in place, undesirable apps that fool users can still slip into the Google Play store.
If you installed Dubsmash 2 (package name “com.table.hockes”), you can delete the app by going into Settings -> Apps -> find “Settings IS” and then uninstall the app.
The Avast Mobile Security application detects this threat as Android:Clicker. SHA-256 hash: de98363968182c27879aa6bdd9a499e30c6beffcc10371c90af2edc32350fac4
Thank you Nikolaos Chrysaidos for your help with the analysis
When it comes to cybercrime, it’s always better to be in the know. Here are a few ways that web attacks can find their way onto your device. Don’t be fooled — most cybercrooks design attacks to take place where you’d least expect it.
Social engineering preys on human weakness
“A lot of attacks are still using social engineering techniques; phishing emails – ways of convincing the user to give up valuable information,” said Avast CEO Vince Steckler.
In a phishing or spearphishing attack, hackers use email messages to trick people into providing sensitive information, click on links, or download malware. The emails are seemingly sent from organizations or individuals the potential victims would normally get emails from, making them even more deceptive. Last July, Avast took a look at the Tinba Trojan, banking malware that used spearphishing to target its victims.
An example of an injected form from Tinba Trojan targeting U.S. Bank customers.
Web attacks also take place through SMS Text Phishing, also known as SMSishing. This method has become one of the most popular ways in which malicious threats are transmitted on Android devices. These text messages include links that contain malware, and upon clicking them, the malicious program is downloaded to the user’s device. These programs often operate as SMS worms capable of sending messages, removing apps and files, and stealing confidential information from the user.
Malicious apps attempt to fool you
Malicious programs can disguise themselves as real programs by hiding within popular apps or games. In February, we examined malicious apps posing as games on Google Play that infected millions of users with adware. In the case of malicious apps, cybercrooks tamper with the app’s code, inserting additional features and malicious programs that infect devices. As a result, the malware can attempt to use SMSishing in order to collect additional data.
The Durak card game app was the most widespread of the malicious apps with 5 – 10 million installations according to Google Play.
Ransomware uses scare tactics that really work
Another name that made headlines was a group of malware dubbed ransomware, such as CryptoLocker, and its variants Cryptowall, Prison Locker, PowerLocker, and Zerolocker. The most widespread is Cryptolocker, which encrypts data on a computer and demands money from the victim in order to provide the decryption key. Avast detects and protects its users from CryptoLocker and GameoverZeus.
Make sure you back up important files on a regular basis to avoid losing them to ransomware. Ransomware made its way from desktop to Android during the year, and Avast created a Ransomware Removal app to eliminate Android ransomware and unlocks encrypted files for free.
Count on Avast apps to keep mobile malware at bay
To keep your devices protected from other ransomware, make sure to also install Avast Free Mobile Security & Antivirus from the Google Play store. It can detect and remove the malware before it is deployed.
Install Avast Ransomware Removal to find out if your Android devices are infected and to get rid of an infection. Avast Ransomware Removal will tell you if your phone has ransomware on it. If you are infected, it will eliminate the malware. Android users who are clean can use the free app to prevent an infection from happening.Once installed, you can easily launch the app to scan the device, remove the virus, and then decrypt your hijacked files.