W32.Ramnit

Updated: October 23, 2011 Virus 4 Comments

W32.Ramnit is a worm that propagates on removable drives infecting executable files it founds. W32.Ramnit will also copy itself on the recycle bin and creates Autorun.Inf file on each drives to run itself when the drive is accessed.

Also Identified As:
Win32/Zbot.A – AVG
W32/Infector.Gen2 – Avira
Win32/Ramnit.A – CA
Win32.Rmnet – Dr.Web
W32.Infector – Ikarus
Type_Win32 – Kaspersky
W32/Ramnit.a – McAfee
Virus:Win32/Ramnit.A – MMPC
W32/Patched-I – Sophos
PE_RAMNIT.A – Trend Micro

Damage Level: Medium

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

Characteristics
W32.Ramnit may infect Windows executable files and HTML files. The virus injects a code to default Internet browser’s process to hide its malicious operation inside the compromised PC. With this method, the virus is able to bypass firewall and allows a remote attacker to secure an access on infected computer through backdoor port. It also receives instructions from a remote Command and Control Server (C&C). Using a proprietary set of rules, the virus will connect to remote server on port 443.

Distribution
W32.Ramnit employs several ways to spread itself and infect target computer. Malicious web sites may download the virus on visitor’s computer by exploiting Internet browser’s vulnerabilities. Virus is also sent as an attached file to spam email messages masquerading as useful or valuable file. The email contains persuasive message so that victims may execute the attached fie.

Once inside the system, W32.Ramnit starts to propagate locally by infecting file that has EXE, DLL, HTM or HTML extensions.

[cf]regis[/cf] [cf]files[/cf]

How to Remove W32.Ramnit

1. Temporarily Disable System Restore (Windows Me/XP). [how to]
2. To be able to identify even the most recent variant of W32.Ramnit, open your antivirus application and update the virus definition file.

3. Start Windows in Safe Mode with Networking.
- From a power-off state, turn on the computer and press F8 on your keyboard repeatedly.
- Your computer will display Windows Advanced Boot Options menu. Please select Safe Mode with Networking.
- The system will now boot Windows and loads only necessary drivers and files.

4. Open your antivirus program and run a full system scan. After the scan, delete all infected items. If unable to delete, better place them in quarantine. Once the scan is complete, please proceed with the next step.

Scan with Norton Power Eraser:

Additional virus removal tool like Norton Power Eraser provides deep scanning technology to eliminate other threats not detected by a normal virus scan. Use this tool with extra caution.

5. Go to this link and download Norton Power Eraser.
6. Once the download completes, double click on the file NPE.exe to run the program.
7. It will prompt for End User License Agreement, click on Accept to continue.
8. On NPE main window, click on Scan. Then select Exclude Rootkit Scan. Click on Continue to proceed.
9. Virus scanning may take some time. After running the scan, NPE will display the scan result.

Important! If there are any detected threats under Suspicious, remove the check mark. Only threats in Detected category are necessary to remove at this point. Make sure that you mark the Create System Restore Point before proceeding with the fix.

10. Now click on Fix to start removing the threats including W32.Ramnit remnants if there are any.
11. When done, Norton Power Eraser will restart the computer. Then after a reboot, it will initialize and display the eliminated threats.
12. You may now close Norton Power Eraser.

Alternative Removal Method for W32.Ramnit

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

If W32.Ramnit enters the computer, there is a big chance that Windows files, registry entries and other essential components are also infected. System Restore can reinstate clean system files by restoring the configuration to an earlier date. The method also replaces compromised files with a clean version. If you have a saved restore point before W32.Ramnit infiltrates the PC, we highly encourage you to execute this procedure if none of the above works. You may proceed with Windows System Restore, click here to see the full procedure.

Option 2 : W32.Ramnit manual uninstall guide

IMPORTANT! Manual removal of W32.Ramnit 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.
- Press Ctrl+Alt+Del on your keyboard.
- When Windows Task Manager appears, look for W32.Ramnit 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.
- Just before Windows logo begins to load press F8 on your keyboard.
- On Windows Advanced Boot Options, select Safe Mode and press Enter.

4. Delete all files dropped by W32.Ramnit.
- 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: