Security researchers at Dr.Web have reported a new Trojan, dubbed BackDoor.TeamViewer.49. According to the security firm, the threat is designed to install TeamViewer on targeted systems. Why is BackDoor.TeamViewer.49 doing that? To transmit web traffic to specific servers through using the host as a proxy server. The Trojan was discovered and analyzed just recently, and its distribution process is quite complex and multi-stage.
Threat Summary
| Name | BackDoor.TeamViewer.49 |
| Type | Backdoor Trojan |
| Short Description | The Trojan is used to relay Web traffic and hide the cyber criminals’ real IP address. |
| Symptoms | The victim installs a malicious Flash update package. |
| Distribution Method | Via a Trojan dropper and a malicious Flash update package. |
| Detection Tool |
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| User Experience | Join Our Forum to Discuss BackDoor.TeamViewer.49. |
Technical Specifications of BackDoor.TeamViewer.49
Dr.Web reports that the Trojan is spread with the help of a Trojan dropper – Trojan.MulDrop6.39120. Softpedia says that the Trojan’s initial infection takes place via a corrupted Adobe Flash update package. In fact, Trojan.MulDrop6.39120 is spread online bundled with the Flash package. Once the potential victim installs the Flash update, the Trojan dropper is installed along with the TeamViewer app.
Contrary to what you may think TeamViewer is dropped for – taking over the compromised computer, obtaining sensitive information – it’s used for something else.
Cyber criminals replace TeamViewer’s avicap32.dll with a malicious version containing BackDoor.TeamViewer.49.
The Trojan’s main payload is incorporated into the avicap32.dll library. Trojan.MulDrop6.39120 runs TeamViewer that automatically loads the library to the computer’s memory. All lines, imports, and functions of TeamViewer’s process are actively implemented by this malicious library. The most critical parts of the Trojan’s code are encrypted with base64 and RC4.
Once TeamViewer is set and running, BackDoor.TeamViewer.49 connects to a command & control server using an encrypted channel, and awaits instructions. According to Dr.Web’s research, the analyzed versions mainly operate as a Web proxy, relaying traffic it receives from the command server to the Internet. This is how cyber criminals mask their real IP address.
Dr.Web also reports that the Trojan can execute the following commands received over HTTPS:
- disconnect—terminate the connection;
- idle—maintain the connection;
- updips—update the auth_ip list with the one specified in the command received;
- connect—connect to the specified host server. The command must consist of the following parameters:
- ip—host server’s IP address;
- auth_swith—use authorization. If the value is set to “1”, the Trojan receives the auth_login and auth_pass parameters. If the value is “0”, the Trojan gets the auth_ip parameter. Otherwise, the connection will not be established;
- auth_ip—IP authentication;
- auth_login—login;
- auth_pass—password.
How Can Users Protect Their PCs from BackDoor.TeamViewer.49?
As with other Trojans, the most secure way to prevent an infection is via having an active anti-malware protection on the system. If you have been affected, refer to the removal steps below to try and remove the Trojan completely.
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Preparation before removing BackDoor.TeamViewer.49.
Before starting the actual removal process, we recommend that you do the following preparation steps.
- Make sure you have these instructions always open and in front of your eyes.
- Do a backup of all of your files, even if they could be damaged. You should back up your data with a cloud backup solution and insure your files against any type of loss, even from the most severe threats.
- Be patient as this could take a while.
- Scan for Malware
- Fix Registries
- Remove Virus Files
Step 1: Scan for BackDoor.TeamViewer.49 with SpyHunter Anti-Malware Tool
Step 2: Clean any registries, created by BackDoor.TeamViewer.49 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 BackDoor.TeamViewer.49 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.Step 3: Find virus files created by BackDoor.TeamViewer.49 on your PC.
1.For Windows 8, 8.1 and 10.
For Newer Windows Operating Systems
1: On your keyboard press + R and write explorer.exe in the Run text box and then click on the Ok button.
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.
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 navigation box to fill up in case the PC is looking for the file and hasn't found it yet.
2.For Windows XP, Vista, and 7.
For Older Windows Operating Systems
In older Windows OS's the conventional approach should be the effective one:
1: Click on the Start Menu icon (usually on your bottom-left) and then choose the Search preference.
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.
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.
BackDoor.TeamViewer.49 FAQ
What Does BackDoor.TeamViewer.49 Trojan Do?
The BackDoor.TeamViewer.49 Trojan is a malicious computer program designed to disrupt, damage, or gain unauthorized access to a computer system. It can be used to steal sensitive data, gain control over a system, or launch other malicious activities.
Can Trojans Steal Passwords?
Yes, Trojans, like BackDoor.TeamViewer.49, can steal passwords. These malicious programs are designed to gain access to a user's computer, spy on victims and steal sensitive information such as banking details and passwords.
Can BackDoor.TeamViewer.49 Trojan Hide Itself?
Yes, it can. A Trojan can use various techniques to mask itself, including rootkits, encryption, and obfuscation, to hide from security scanners and evade detection.
Can a Trojan be Removed by Factory Reset?
Yes, a Trojan can be removed by factory resetting your device. This is because it will restore the device to its original state, eliminating any malicious software that may have been installed. Bear in mind that there are more sophisticated Trojans that leave backdoors and reinfect even after a factory reset.
Can BackDoor.TeamViewer.49 Trojan Infect WiFi?
Yes, it is possible for a Trojan to infect WiFi networks. When a user connects to the infected network, the Trojan can spread to other connected devices and can access sensitive information on the network.
Can Trojans Be Deleted?
Yes, Trojans can be deleted. This is typically done by running a powerful anti-virus or anti-malware program that is designed to detect and remove malicious files. In some cases, manual deletion of the Trojan may also be necessary.
Can Trojans Steal Files?
Yes, Trojans can steal files if they are installed on a computer. This is done by allowing the malware author or user to gain access to the computer and then steal the files stored on it.
Which Anti-Malware Can Remove Trojans?
Anti-malware programs such as SpyHunter are capable of scanning for and removing Trojans from your computer. It is important to keep your anti-malware up to date and regularly scan your system for any malicious software.
Can Trojans Infect USB?
Yes, Trojans can infect USB devices. USB Trojans typically spread through malicious files downloaded from the internet or shared via email, allowing the hacker to gain access to a user's confidential data.
About the BackDoor.TeamViewer.49 Research
The content we publish on SensorsTechForum.com, this BackDoor.TeamViewer.49 how-to removal guide included, is the outcome of extensive research, hard work and our team’s devotion to help you remove the specific trojan problem.
How did we conduct the research on BackDoor.TeamViewer.49?
Please note that our research is based on an independent investigation. We are in contact with independent security researchers, thanks to which we receive daily updates on the latest malware definitions, including the various types of trojans (backdoor, downloader, infostealer, ransom, etc.)
Furthermore, the research behind the BackDoor.TeamViewer.49 threat is backed with VirusTotal.
To better understand the threat posed by trojans, please refer to the following articles which provide knowledgeable details.