The Teamfostealer Trojan is a dangerous weapon used against computer users worldwide. It infects mainly via infected software installers. Our article gives an overview of its behavior according to the collected samples and available reports, also it may be helpful in attempting to remove the virus.
Threat Summary
| Name | Teamfostealer Trojan |
| Type | Trojan |
| Short Description | The Teamfostealer Trojan is a computer virus that is designed to silently infiltrate computer systems. |
| Symptoms | The victims may not experience any apparent symptoms of infection. |
| Distribution Method | Software Vulnerabilities, Freeware Installations, Bundled Packages, Scripts and others. |
| Detection Tool | See If Your System Has Been Affected by malware Download Malware Removal Tool |
| User Experience | Join Our Forum to Discuss Teamfostealer Trojan. |
Teamfostealer Trojan – Distribution Methods
The Teamfostealer Trojan is a very dangerous malware which was recently captured in an active campaign. The method of distribution is seen as very effective — the criminal collective behind the Teamfostealer Trojan is currently embedding the Trojan installation code in application installers of one of the most popular system utilities — Team Viewer. This is one of the most widely used solutions for remote logins.
This mechanism is primarily done by taking the real installers and modifying them to include the virus code. The hacking collective will download the legitimate setup file and modify it accordingly. The files are then delivered to the targets using a series of tactics — concentrating on a given approach or using several ones at once in order to maximize the number of possible infected computers.
At the moment the captured samples have been found posted on hacker-controlled sites. This means that some ind of a redirect scheme is being employed in order to lure them into downloading and running the malicious files. There are several popular approaches that can be undertaken:
- Email-based Phishing Campaigns — The hackers can plan an email-based phishing campaign which sends out messages that pose as legitimate notifications by welll-known companies or services. The criminals will spoof the original body design and text layout of the companies which can make it almost impossible to distinguish them from the real ones. The malicious Team Viewer files that contain the Teamfostealer Trojan installation code can be linked in the body contents or directly attached to the emails.
- Malicious Sites — A similar mechanism is the creation and maintenance Internet pages that look like the real landing pages of well-known search engines, download portals, company profiles pages and etc. They are hosted on similar sounding domain names that are very difficult to differentiate from the legitimate ones. Additionally they can include security certificates that can build the feeling that the accessed pages are safe.
- Bundle Downloads — The Teamfostealer Trojan can be embedded in application installers across the Internet. They are very similar to the infected application installers in a sense that they are made by modifying legitimate files with virus code.
- File-sharing networks — BitTorrent and other P2P platforms are very popular at sending both legitimate and pirate content. As such they are among the most dangerous conduits of malware files.
- Browser Hijackers — The infections can also be be caused through the use of dangerous plugins made for the most popular web browsers, alternatively known as hijackers. They are widely available from their associated repositories or download sites and promoted through elaborate descriptions and fake user reviews. When installed they will change the default settings in order to redirect the victims to a hacker-controlled web page. At the same time the virus infection will also be triggered.
Various other methods can be used in future campaigns. Take note that the delivered malicious Team Viewer packages are self-extracting archives (SFX/SEA) which is not the way the vendor has intended it to be. This is yet another warning sign that the package may be malicious in nature.
Teamfostealer Trojan – Detailed Description
The Teamfostealer Trojan will run the typical behavior patterns as observed by many other similar threats. Instead of the legitimate Team Viewer application the dangerous Trojan will be deployed to the systems. The first commands that are to be run will be to drop spyware data inside the User’s temporary folder as files that have typical Windows-related data which doesn’t raise any alarms of suspicion.
The malicious TeamViewer.exe will then load these files and launch a data collection module which will acquire the information and send it to the hacker operators via a network connection. The following information is confirmed to be extracted:
- Operating System
- OS Architecture
- Computer Name
- User Name
- RAM size
- Presence of AV Products
- Administrator Privilege
So far the Trojan has been found to focus mainly on data retrieval, possibly extending this feature to personal information as well. If this is done the engine will be programmed tool acquire strings that can directly expose the identity of the victim users. Such include their names, address, phone number, interests and any stored account credentials. If the Trojan interacts with the Windows Volume Manager it will be able to access removable storage devices and network shares as well. Successful exploitation of this behavior can help facilitate crimes such as identity theft and financial abuse.
Other malicious behavior that can be exhibited includes the execution of other modules in future versions. A common component is the persistent installation — it will set up the infection in such a way that the malicious code will be started every time the computer is powered on. This means that most of the manual user recovery instructions will not work as the virus will disable the access to the recovery menus and boot options.
An associated practice is the launch of a security bypass which will scan the infected machine for the presence of any anti-virus products and actively disable them. This is an effective solution against all services that can block the Trojan’s operations: firewalls, anti-virus products, virtual machine hosts and etc.
One of the most dangerous consequences of having such infections active on a host computer is when additional payloads are delivered. This is a very dangerous scenario as it has already disabled the security on the target computers and all dropped malware will have the ability to unfold all of their capabilities. The forthcoming campaign might contain a radically changed engine that will follow another set of behavior patterns.
Remove Teamfostealer Trojan Trojan
If your computer system got infected with the Teamfostealer Trojan Trojan, you should have a bit of experience in removing malware. You should get rid of this Trojan as quickly as possible before it can have the chance to spread further and infect other computers. You should remove the Trojan and follow the step-by-step instructions guide provided below.
Note! Your computer system may be affected by Teamfostealer Trojan and other threats.
Scan Your PC with SpyHunter
SpyHunter is a powerful malware removal tool designed to help users with in-depth system security analysis, detection and removal of Teamfostealer Trojan.
Keep in mind, that SpyHunter’s scanner is only for malware detection. If SpyHunter detects malware on your PC, you will need to purchase SpyHunter’s malware removal tool to remove the malware threats. Read our SpyHunter 5 review. Click on the corresponding links to check SpyHunter’s EULA, Privacy Policy and Threat Assessment Criteria.
To remove Teamfostealer Trojan follow these steps:
Boot Your PC Into Safe Mode
1. For Windows XP, Vista and 7.
2. For Windows 8, 8.1 and 10.
Fix registry entries created by malware and PUPs on your PC.For Windows XP, Vista and 7 systems:
1. Remove all CDs and DVDs, and then Restart your PC from the “Start” menu.
2. Select one of the two options provided below:
– For PCs with a single operating system: Press “F8” repeatedly after the first boot screen shows up during the restart of your computer. In case the Windows logo appears on the screen, you have to repeat the same task again.
– For PCs with multiple operating systems: Тhe arrow keys will help you select the operating system you prefer to start in Safe Mode. Press “F8” just as described for a single operating system.
3. As the “Advanced Boot Options” screen appears, select the Safe Mode option you want using the arrow keys. As you make your selection, press “Enter“.
4. Log on to your computer using your administrator account
While your computer is in Safe Mode, the words “Safe Mode” will appear in all four corners of your screen.
Step 1: Open up the Start Menu.
Step 2: Click on the Power button (for Windows 8 it is the little arrow next to the “Shut Down” button) and whilst holding down “Shift” click on Restart.
Step 3: After reboot, a blue menu with options will appear. From them you should choose Troubleshoot.
Step 4: You will see the Troubleshoot menu. From this menu choose Advanced Options.
Step 5: After the Advanced Options menu appears, click on Startup Settings.
Step 6: From the Startup Settings menu, click on Restart.
Step 7: A menu will appear upon reboot. You can choose any of the three Safe Mode options by pressing its corresponding number and the machine will restart.
Some malicious scripts may modify the registry entries on your computer to change different settings. This is why cleaning your Windows Registry Database is recommended. Since the tutorial on how to do this is a bit long and tampering with registries could damage your computer if not done properly you should refer and follow our instructive article about fixing registry entries, especially if you are unexperienced in that area.
Find files created by Teamfostealer Trojan
1. For Windows 8, 8.1 and 10. 2. For Windows XP, Vista, and 7.For Newer Windows Operating Systems
Step 1:
On your keyboard press + R and write explorer.exe in the Run text box and then click on the Ok button.
Step 2:
Click on your PC from the quick access bar. This is usually an icon with a monitor and its name is either “My Computer”, “My PC” or “This PC” or whatever you have named it.
Step 3:
Navigate to the search box in the top-right of your PC’s screen and type “fileextension:” and after which type the file extension. If you are looking for malicious executables, an example may be “fileextension:exe”. After doing that, leave a space and type the file name you believe the malware has created. Here is how it may appear if your file has been found:
N.B. We recommend to wait for the green loading bar in the navination box to fill up in case the PC is looking for the file and hasn’t found it yet.
For Older Windows Operating Systems
In older Windows OS’s the conventional approach should be the effective one:
Step 1:
Click on the Start Menu icon (usually on your bottom-left) and then choose the Search preference.
Step 2:
After the search window appears, choose More Advanced Options from the search assistant box. Another way is by clicking on All Files and Folders.
Step 3:
After that type the name of the file you are looking for and click on the Search button. This might take some time after which results will appear. If you have found the malicious file, you may copy or open its location by right-clicking on it.
Now you should be able to discover any file on Windows as long as it is on your hard drive and is not concealed via special software.
Use SpyHunter to scan for malware and unwanted programs
Scan your PC and Remove Teamfostealer Trojan with SpyHunter Anti-Malware Tool and back up your data
1. Install SpyHunter to scan for Teamfostealer Trojan and remove them.2. Scan with SpyHunter, Detect and Remove Teamfostealer Trojan.
Back up your data to secure it from malware in the future.It is recommended to run a scan before purchasing the full version of the software to make sure that the current version of the malware can be detected by SpyHunter. Click on the corresponding links to check SpyHunter’s EULA, Privacy Policy and Threat Assessment Criteria.
Step 2: Guide yourself by the download instructions provided for each browser.
Step 3: After you have installed SpyHunter, wait for it to update automatically.
Step 1: After the update process has finished, click on the ‘Malware/PC Scan’ tab. A new window will appear. Click on ‘Start Scan’.
Step 2: After SpyHunter has finished scanning your PC for any files of the associated threat and found them, you can try to get them removed automatically and permanently by clicking on the ‘Next’ button.
Step 3: If any threats have been removed, it is highly recommended to restart your PC.
Back up your data to secure it against attacks in the future
IMPORTANT! Before reading the Windows backup instructions, we highly recommend to back up your data with a cloud backup solution and insure your files against any type of loss, even from the most severe threats. We recommend you to read more about it and to download SOS Online Backup .
Martin Beltov
Martin graduated with a degree in Publishing from Sofia University. As a cyber security enthusiast he enjoys writing about the latest threats and mechanisms of intrusion.
Follow Me:
- Guide 1: How to Remove Teamfostealer Trojan from Windows.
- Guide 2: Get rid of Teamfostealer Trojan from Mac OS X.
- Guide 3: Remove Teamfostealer Trojan from Google Chrome.
- Guide 4: Erase Teamfostealer Trojan from Mozilla Firefox.
- Guide 5: Uninstall Teamfostealer Trojan from Microsoft Edge.
- Guide 6: Remove Teamfostealer Trojan from Safari.
- Guide 7: Eliminate Teamfostealer Trojan from Internet Explorer.
Windows Mac OS X Google Chrome Mozilla Firefox Microsoft Edge Safari Internet Explorer
How to Remove Teamfostealer Trojan from Windows.
Step 1: Boot Your PC In Safe Mode to isolate and remove Teamfostealer Trojan
Step 2: Uninstall Teamfostealer Trojan and related software from Windows
Here is a method in few easy steps that should be able to uninstall most programs. No matter if you are using Windows 10, 8, 7, Vista or XP, those steps will get the job done. Dragging the program or its folder to the recycle bin can be a very bad decision. If you do that, bits and pieces of the program are left behind, and that can lead to unstable work of your PC, errors with the file type associations and other unpleasant activities. The proper way to get a program off your computer is to Uninstall it. To do that:
Follow the instructions above and you will successfully uninstall most programs.Step 3: Clean any registries, created by Teamfostealer Trojan on your computer.
The usually targeted registries of Windows machines are the following:
- HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
- HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnce
- HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
You can access them by opening the Windows registry editor and deleting any values, created by Teamfostealer Trojan there. This can happen by following the steps underneath:
Tip: To find a virus-created value, you can right-click on it and click "Modify" to see which file it is set to run. If this is the virus file location, remove the value.Before starting "Step 4", please boot back into Normal mode, in case you are currently in Safe Mode.
This will enable you to install and use SpyHunter 5 successfully.
Windows Mac OS X Google Chrome Mozilla Firefox Microsoft Edge Safari Internet Explorer
Get rid of Teamfostealer Trojan from Mac OS X.
Step 1: Uninstall Teamfostealer Trojan and remove related files and objects
1. Hit the ⇧+⌘+U keys to open Utilities. Another way is to click on “Go” and then click “Utilities”, like the image below shows:
- Go to Finder.
- In the search bar type the name of the app that you want to remove.
- Above the search bar change the two drop down menus to “System Files” and “Are Included” so that you can see all of the files associated with the application you want to remove. Bear in mind that some of the files may not be related to the app so be very careful which files you delete.
- If all of the files are related, hold the ⌘+A buttons to select them and then drive them to “Trash”.
In case you cannot remove Teamfostealer Trojan via Step 1 above:
In case you cannot find the virus files and objects in your Applications or other places we have shown above, you can manually look for them in the Libraries of your Mac. But before doing this, please read the disclaimer below:
You can repeat the same procedure with the following other Library directories:
→ ~/Library/LaunchAgents
/Library/LaunchDaemons
Tip: ~ is there on purpose, because it leads to more LaunchAgents.
Step 2: Scan for and remove malware from your Mac
When you are facing problems on your Mac as a result of unwanted scripts, programs and malware, the recommended way of eliminating the threat is by using an anti-malware program. Combo Cleaner offers advanced security features along with other modules that will improve your Mac’s security and protect it in the future.
Windows Mac OS X Google Chrome Mozilla Firefox Microsoft Edge Safari Internet Explorer
Remove Teamfostealer Trojan from Google Chrome.
Step 1: Start Google Chrome and open the drop menu
Step 2: Move the cursor over "Tools" and then from the extended menu choose "Extensions"
Step 3: From the opened "Extensions" menu locate the unwanted extension and click on its "Remove" button.
Step 4: After the extension is removed, restart Google Chrome by closing it from the red "X" button at the top right corner and start it again.
Windows Mac OS X Google Chrome Mozilla Firefox Microsoft Edge Safari Internet Explorer
Erase Teamfostealer Trojan from Mozilla Firefox.
Step 1: Start Mozilla Firefox. Open the menu window
Step 2: Select the "Add-ons" icon from the menu.
Step 3: Select the unwanted extension and click "Remove"
Step 4: After the extension is removed, restart Mozilla Firefox by closing it from the red "X" button at the top right corner and start it again.
Windows Mac OS X Google Chrome Mozilla Firefox Microsoft Edge Safari Internet Explorer
Uninstall Teamfostealer Trojan from Microsoft Edge.
Step 1: Start Edge browser.
Step 2: Open the drop menu by clicking on the icon at the top right corner.
Step 3: From the drop menu select "Extensions".
Step 4: Choose the suspected malicious extension you want to remove and then click on the gear icon.
Step 5: Remove the malicious extension by scrolling down and then clicking on Uninstall.
Windows Mac OS X Google Chrome Mozilla Firefox Microsoft Edge Safari Internet Explorer
Remove Teamfostealer Trojan from Safari.
Step 1: Start the Safari app.
Step 2: After hovering your mouse cursor to the top of the screen, click on the Safari text to open its drop down menu.
Step 3: From the menu, click on "Preferences".
Step 4: After that, select the 'Extensions' Tab.
Step 5: Click once on the extension you want to remove.
Step 6: Click 'Uninstall'.
A pop-up window will appear asking for confirmation to uninstall the extension. Select 'Uninstall' again, and the Teamfostealer Trojan will be removed.
Windows Mac OS X Google Chrome Mozilla Firefox Microsoft Edge Safari Internet Explorer
Eliminate Teamfostealer Trojan from Internet Explorer.
Step 1: Start Internet Explorer.
Step 2: Click on the gear icon labeled 'Tools' to open the drop menu and select 'Manage Add-ons'
Step 3: In the 'Manage Add-ons' window.
Step 4: Select the extension you want to remove and then click 'Disable'. A pop-up window will appear to inform you that you are about to disable the selected extension, and some more add-ons might be disabled as well. Leave all the boxes checked, and click 'Disable'.
Step 5: After the unwanted extension has been removed, restart Internet Explorer by closing it from the red 'X' button located at the top right corner and start it again.
