Trojan.Downbot

Trojan.Downbot is a computer Trojan that will download more threats on the already infected computer. The Trojan focuses on several known organizations like private companies and government agencies worldwide. The objective of the attack as foreseen by security expert is to steal sensitive information from these organizations. Trojan.Downbot will arrive on target computer by a drive-by download method.

Damage Level: Medium

Systems Affected: Windows 9x, 2000, XP, Windows Vista

Characteristics
Once it is run, Trojan.Downbot will drop harmful files and make several changes on computer settings. The attacks are composing of three levels – email spamming, computer infection and thorough backdoor usage. The last level of using a backdoor allows the attackers to take full control of the infected system.
When the Trojan is loaded on the PC, it may perform other tasks including the following:

  • Download more files from a remote server.
  • Deactivate the Trojan for specified time.
  • Open a backdoor and connect to specified IP address.
  • Send and receive commands from a remote attacker.

Distribution
As of this writing, only known channel used by Trojan.Downbot to spread a copy is through email campaign. The message of this email contains a link that points to an executable file or it may directly carry the file as attachment.

How to Remove Trojan.Downbot

Systematic procedures to get rid of the threat are presented on this section. Make sure to scan the computer with suggested tools and scanners.

NOTE: We suggest that you PRINT or BOOKMARK this guide. There are steps that we may have to restart the computer in order to successfully remove the threat.

Step 1 : Run a scan with your antivirus program

1. First thing you should do is reboot the computer in Safe Mode with Networking to avoid Trojan.Downbot from loading at start-up.

Remove all media such as Memory Card, cd, dvd, and USB devices. Then, restart the computer and please do the following:

Boot in Safe Mode on Windows XP, Windows Vista, and Windows 7 system
a) Before Windows begins to load, press F8 on your keyboard.
b) It will display the Advanced Boot Options menu. Select Safe Mode.

Start computer in Safe Mode using Windows 8 and Windows 10
a) Close any running programs on your computer.
b) Get ready to Start Windows. On your keyboard, Press and Hold Shift key and then, click on Restart button.
c) It will prompt you with options, please click on Troubleshoot icon.
d) Under Troubleshoot window, select Advanced Options.
e) On next window, click on Startup Settings icon.
f) Lastly, click on Restart button on subsequent window.
g) When Windows restarts, present startup options with numbers 1 - 9. Select "Enable Safe Mode with Networking" or number 5.

Startup Options

h) Windows will now boot on Safe Mode with Networking. Proceed with virus scan as the next step.

2. Once Windows is running under Safe Mode with Networking, open your antivirus program and download the most recent update. This method ensures that your antivirus program can detect even newer variants of Trojan.Downbot.

Updating your antivirus software is a one-click process. Please refer to your software manual for complete instructions.

3. Once updating is finished, run a full system scan. After the scan, delete all infected items. If unable to clean or delete, better place the threat in quarantine.

Step 2: Run another test with online virus scanner

Another way to remove Trojan.Downbot without the need to install additional antivirus software is to perform a thorough scan with free online virus scanner. It can be found on websites of legitimate antivirus and security provider.

1. Click the button below to proceed to the list of suggested Online Virus Scanner. Choose your desired provider. You can run each scan individually, one at a time, to ensure that all threats will be removed from the computer. This may require plug-ins, add-on or Activex object, please install if you want to proceed with scan.

Online Virus Scan

2. After completing the necessary download, your system is now ready to scan and remove Trojan.Downbot and other kinds of threats.
3. Select an option in which you can thoroughly scan the computer to make sure that it will find and delete entirely all infections not detected on previous scan.
4. Remove or delete all detected items.
5. When scanning is finished, you may now restart the computer in normal mode.

Alternative Removal Procedures for Trojan.Downbot

Option 1 : Use Windows System Restore to return Windows to previous state

During an infection, Trojan.Downbot drops various files and registry entries. The threat intentionally hides system files by setting options in the registry. With these rigid changes, the best solution is to return Windows to previous working state is through System Restore.

To verify if System Restore is active on your computer, please follow the instructions below to access this feature.

Access System Restore on Windows XP, Windows Vista, and Windows 7

a) Go to Start Menu, then under 'Run' or 'Search Program and Files' field, type rstrui.
b) Then, press Enter on the keyboard to open System Restore Settings.

rstrui-win7

Open System Restore on Windows 8 and Windows 10

a) Hover your mouse cursor to the lower left corner of the screen and wait for the Start icon to appear.
b) Right-click on the icon and select Run from the list. This will open a Run dialog box.
c) Type rstrui on the 'Open' field and click on OK to initiate the command.

rstrui-win8

If previous restore point is saved, you may proceed with Windows System Restore. Click here to see the full procedure.

Option 2 : Trojan.Downbot manual uninstall guide

IMPORTANT! Manual removal of Trojan.Downbot requires technical skills. Deleting system files and registry entries by mistake may result to total disability of Windows system. We advise you to perform a backup of registry before proceeding with this guide.

1. Kill any running process that belongs to Trojan.Downbot.

- Press Ctrl+Alt+Del on your keyboard.
- When Windows Task Manager appears, look for Trojan.Downbot files (refer to Technical Reference) and click End Process.

End Task

2. Delete all registry entries that belong to this malware.

- Press [Windows Key]+R on your keyboard.
- In the 'Open' dialog box, type regedit and press Enter. This will open registry editor.
- Find and delete registry entries as mentioned in Technical Reference section below.
- Close registry editor. Changes made will be save automatically.

Run Regedit

3. Scan the computer with antivirus program.

- Connect to Internet and open your antivirus software. Please update to obtain the latest database and necessary files.
- Restart the computer in Safe Mode using the procedures above.
- Open your anti-virus program and thoroughly run a scan on the computer. Delete/Quarantine all identified threats to remove Trojan.Downbot effectively.

4. Delete all files dropped by Trojan.Downbot.

- While still in Safe Mode, search and delete malicious files. Please refer to 'Technical Reference'. Make sure that you execute 'End Task' first before deleting the file. Otherwise, the system will not let you perform this action.

Technical Reference

Associated Files and Folders:Added Registry Entries:
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About Marco Mathew

Marco Mathew works as Windows Network administrator before establishing precisesecurity.com. Now, Marco is dedicating full-time to help computer users' fight viruses, malware, trojan, worms, adware, and potentially unwanted programs.

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