Protecting over 230 million PCs, Macs, & Mobiles – more than any other antivirus


Posts Tagged ‘malware’
September 30th, 2015

Why independent testing is good for Avast Antivirus


Avast Free Antivirus just received another AV-Test certification for its stellar protection against real-world threats, performance in daily use, and usability.


Yay! It’s like collecting another trophy for the display case or another blue ribbon to hang on the wall, but what does it really mean? How is this type of testing useful for you, our customers?

Ondrej Vlcek, Avast’s Chief Operations Officer explains,

Because of the overwhelming growth of malware targeting consumers and businesses, labs like AV-Test Institute have become an invaluable independent source of data to Avast. Their research has influenced our engineers to expand their knowledge of malware, revolutionize diagnostic and detection methods, and facilitate strategies to get real-time updates to hundreds of millions of people who put their trust in our antivirus products.”

Here’s a little background on the testing lab.

AV-Test Institute is an independent lab designed specifically for testing and researching malware. Located in Magdeburg, Germany, they inhabit 1200m² (12,900 ft²) of space with 3 server rooms and a variety of main and secondary laboratories.

Read more…

September 9th, 2015

What does the Avast Sandbox do?

The Sandbox is like a hamster ball. It keeps potential troublemakers isolated.

The Sandbox is like a hamster ball. It keeps potential troublemakers isolated.

The Avast Sandbox lets you run a questionable program without risking your computer.

The Avast Sandbox is a special security feature which allows you to run potentially suspicious applications automatically in a completely isolated environment. This is particularly useful if you don’t completely trust whatever you just downloaded or you visit dodgy websites because programs running within the sandbox have limited access to your files and system, so there is no risk to your computer or any of your other files.

Here’s how it works: By default, if an application is started and Avast detects anything suspicious, it will automatically run the application in the Sandbox.  The advantage of running an application in the Sandbox is that it allows you to check suspicious applications while remaining completely protected against any malicious actions that an infected application might try to perform.

The browser or other application will then open in a special window, indicating that it is being run inside the Sandbox. When the Sandbox is closed, it will be restored to its original state and any downloaded files or changed browser settings will be automatically deleted.

Avast Sandbox

The sandbox window in Avast Premier.

The Avast Sandbox is part of Avast Premier 2015, Avast Internet Security 2015 and Avast Pro Antivirus 2015.


Follow Avast on FacebookTwitterYouTube, and Google+ where we keep you updated on cybersecurity news every day.

September 3rd, 2015

Tiny Banker hidden in modified WinObj tool from Sysinternals

The Tiny Banker Trojan is spread by email attachments.

Tiny Banker aka Tinba Trojan made a name for itself targeting banking customers worldwide. The Avast Virus Lab first analyzed the malware found in the Czech Republic reported in this blog post, Tinybanker Trojan targets banking customers. It didn’t take long for the malware to spread globally attacking customers from various banking behemoths such as Bank of America, Wells Fargo, and RBC Royal Bank, which we wrote about in Tiny Banker Trojan targets customers of major banks worldwide.

This time we will write about a campaign targeting customers of Polish financial institutions.  The Trojan is spread by email attachments pretending to be pictures. The examples of email headers are shown in the following image.


In fact, there are executable files in the zip attachments - IMG-0084(JPEG).JPEG.exe, fotka 1.jpeg.exe. The interesting thing is that the binary looks almost like regular WinObj tool from Systernals, however there are differences: The original version of WinObj has a valid digital signature. The malware doesn’t have any.

Read more…

September 2nd, 2015

Apple jailbroken phones hit with malware

Chinese jailbroken iPhone users targeted

Chinese jailbroken iPhone users targeted

“Biggest iPhone hack ever” attacks jailbroken phones

In what has been called the biggest iPhone hack ever, 250,000 Apple accounts were hijacked. That’s the bad news.

The good news is that most Apple device users are safe. Why? Because the malware dubbed KeyRaider by researchers at Palo Alto Networks, only infects “jailbroken” iOS devices. (there’s that bad news again)

When you jailbreak a device like an iPhone or iPad, it unlocks the device so you can do more with it like customize the look and ringtones, install apps the Apple normally would not allow, and even switch carriers!

The KeyRaider malware entered the jailbroken iPhones and iPads via Cydia, a compatible but unauthorized app store, which allows people to download apps that  didn’t meet Apple’s content guidelines onto their devices. The malware intercepts iTunes traffic on the device to steal data like Apple passwords, usernames, and device GUID (“Globally Unique Identifier” which is your ID number similar to your car’s VIN). Users reported that hackers used their stolen Apple accounts to download applications from the official App Store and make in-app purchases without paying. At least one incident of ransomware was reported.

Chinese iPhone users with jailbroken phones where the primary attack target, but researchers also found incidents in 17 other countries including the United States, France, and Russia.

Read more…

August 20th, 2015

Infected ad networks hit popular websites

Infected ads can be dangerous to your computerIt is frustrating when your antivirus protection stops you from visiting a website that you know and trust, but these days even the most popular websites can fall prey to attacks.

This week security researchers discovered booby-trapped advertisements on popular websites including eBay, The Drudge Report,, and AOL. The ads, some of which can be initiated by a drive-by attack without the user’s knowledge or even any action, infected computers with adware or locked them down with ransomware.

Computer users running older browsers or unpatched software are more likely to get infected with malware just by visiting a website. Avast blocks these infected ads, but to be safe, please use the most updated version. To update your Avast, right-click the Avast Antivirus icon in the systems tray at the bottom-right corner of your desktop. From the menu, select Update.

“This kind of malvertising is a fairly easy way for cybercriminals to deliver adware or another malicious payload. Many websites sell advertising space to ad networks then deliver the targeted ads to your screen,” said Avast Virus Lab researcher Honza Zika. “All Avast users with current virus databases are fully protected against this attack, but those without protection or up-to-date security patches run the risk of being infected with ransomware.”

Read more…

July 24th, 2015

Malware that Just Won’t Give Up on Google Play

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.

Mutant malware

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…

Read more…

Comments off
July 22nd, 2015

Creators of Dubsmash 2 Android Malware Strike Again

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.

The selection of "gaming" apps affected by Clicker-AR malware on the Google Play Store.

The selection of “gaming” apps affected by Clicker-AR malware on the Google 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.

Read more…

July 21st, 2015

Android malware Fobus now targeting users in the U.S., Germany and Spain

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.

Number of users who have encountered Fobus

Number of users who have encountered Fobus

Read more…

July 15th, 2015

One in 10 American mobile users is the target of mobile malware

Avast Antivirus detects and neutralizes malware

Threat analysts and malware researchers in the Avast Virus Lab detect and neutralize threats as soon as they appear.

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.

Read more…

Comments off
July 7th, 2015

Avast Browser Cleanup removes unwanted browser add-ons

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.

Our free utility gets rid of annoying toolbars and restores hijacked searches.

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.

Read more…