W32.Ramnit.B is a computer worm that will spread itself by creating a copy on removable USB drives. W32.Ramnit.B also scans local drives for .exe. dll and .html files. When found, it appends these files with an encrypted payload. The worm will create a back door that will allow distant attacker to carry out malicious actions. It uses rootkit techniques to hide its presence and monitor network traffic of the compromised computer.

Damage Level: Medium

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


W32.Ramnit.B loads by means of removable media devices. When it runs, the worm will create a copy it itself inside the target computer. It may utilize the Autorun function of Windows to execute the worm when accessing the drive or exploit certain weakness on the operating system. Whatever method that materialized to launch the worm, it will create a mutex called INTEL_CEDR_STORE to make sure that only once instance is running.

Then, the worm will create several files under Program Files and User Profile. It will look for presence of removable USB drives and when found, the worm will drop a copy of itself. Accompanying those items is an Autorun.inf file that launches the threat when drive is accessed. Please see Associated Files area for the complete list.

To configure automatic start-up, W32.Ramnit.B will add registry entries. The worm will start on every time Windows starts. A backdoor is essential so that remote attacker can control the infected computer. After opening this transmission protocol, remote attacker may have full access to perform malicious actions on the PC.

    Upload and download files Capture screen shots Update the worm Scan traces of user name and passwords from Internet browser cookies Clear the cookies The most deadly payload that W32.Ramnit.B can bring to a computer is making it unusable. W32.Ramnit.B can destroy the whole operating system simply by deleting essential files.


W32.Ramnit.B spreads through spam email messages and unsecured peer-to-peer connections. Once inside the computer, it attempts to propagate by infecting removable drives like USB Flash Drive, External Hard Drives and Memory Sticks. It may also inject malicious VBS script to .HTML files that operates will fetch more threats when executed.

How to Remove W32.Ramnit.B

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. Scan and remove W32.Ramnit.B with MalwareBytes Anti-Malware

This guide requires a tool called Malwarebytes' Anti-Malware. It is a free tool designed to eradicate various computer infections including W32.Ramnit.B. MBAM scanner and malware removal tool is distributed for free.

1. In order to completely remove W32.Ramnit.B, it is best to download and run the recommended tool. Please click the button below to begin download.

2. After downloading, double-click on the file to install the application. If you are using Windows Vista or Windows 7, right-click on the file and select 'Run as administator' from the list.

3. When User Account Control prompts, please click Yes to proceed with the installation.

4. Follow the prompts and install as 'default' only. There are no changes needed during the installation process.

5. Before the installation procedure ends, MalwareBytes Anti-Malware will ask for database update. please proceed.

6. Click Finish button after installation. Program will run automatically run and you will be prompted to update if newer version of database is available.

7. At this moment, close MalwareBytes Anti-Malware and proceed with the next step.

Run a thorough scan in Safe Mode to remove W32.Ramnit.B

8. Remove all media such as floppy drive, cd, dvd, and USB devices. Then, restart the computer in Safe Mode using the procedures below.

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

a) Before Windows begins to load, press Shift and F8 on your keyboard.

b) On Recovery interface, click on 'See advanced repair options' .

c) Next, click on Troubleshoot option.

d) Then, select Advanced options from the list.

e) Lastly, please choose Windows Startup Settings and click on Restart. When Windows restarts, you will be send to a familiar Advanced Boot Options screen.

f) Select Safe Mode from the selections menu.

9. Once Windows is

running on Safe Mode, find the icon of MalwareBytes Anti-Malware. Double-click to launch the program.

10. Choose Perform full scan on scanner's console to ensure that it thoroughly check the PC for any presence of W32.Ramnit.B and other forms of threats. Click the Scan button to start.

11. Once the scan has completed, Malwarebytes Anti-Malware will issue a list of identified threats. Mark all threats and click on Remove Selected.

12. If it prompts to restart the computer, please reboot Windows normally.

Step 2. Run a scan with your antivirus program

1. Repeat the process of starting Windows in Safe Mode with Networking .

2. Open your antivirus program and download the most recent update. This method ensures that your antivirus program can detect even newer variants of W32.Ramnit.B.

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 on the affected PC. After the scan, delete all infected items. If unable to clean or delete, better place the threat in quarantine.

Step 3: Run another test with online virus scanner

Another way to remove W32.Ramnit.B 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.

2. After completing the necessary download, your system is now ready to scan and remove W32.Ramnit.B 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 W32.Ramnit.B

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

During an infection, W32.Ramnit.B 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.

How to 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.

How to Open System Restore on Windows 8

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.

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

Option 2. W32.Ramnit.B manual uninstall guide

IMPORTANT! Manual removal of W32.Ramnit.B 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 W32.Ramnit.B.

- Press Ctrl+Alt+Del on your keyboard.

- When Windows Task Manager appears, look for W32.Ramnit.B files (refer to Technical Reference) and click End Process .

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.

- Close registry editor. Changes made will be saved automatically.

- Just before Windows logo begins to load press F8 on your keyboard.

Ways to Prevent W32.Ramnit.B Infection

Source: www.precisesecurity.com

Category: Security

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