How to remove Ramnit.A virus?

Hello!

I have been trying to clean a PC from this Ramnit.A virus but so far no success... I have looked into other topics but I guess it gets to a point where each case is a case due to the outcome of logs...
Can anyone help me?

Thanks a lot,
Catarina P

I'm afraid I have very bad news.

Win32/Ramnit.A / Win32/Ramnit.B is a dangerous file infector with IRCBot functionality which infects .exe, and .HTML/HTM files, and opens a back door that compromises your computer. Using this backdoor, a remote attacker can access and instruct the infected computer to download and execute more malicious files. The infected .HTML or .HTM files may be detected as The infected .HTML or .HTM files may be detected as Virus:VBS/Ramnit.A or VBS/Generic. Win32/Ramnit.A!dll is a related file infector often seen with this infection. It too has IRCBot functionality which infects .exe, .dll and .HTML/HTM files and opens a back door that compromises your computer. This component is injected into the default web browser by Worm:Win32/Ramnit.A which is dropped by a Ramnit infected executable file.

-- Note: As with most malware infections, the threat name may be different depending on the anti-virus or anti-malware program which detected it. Each security vendor uses their own naming conventions to identify various types of malware.

• Understanding virus names
• VirusTotal Threat aliases for W32/Ramnit <- Win32.Ramnit!IK, W32.Ramnit!inf, Win32.Rmnet
• VirScan Threat aliases for W32/Ramnit <- Win32/Zbot, PWS.Panda.387, PE_RAMNIT, Trojan/Generic.arhm
• McAfee Threat aliases for W32/Ramnit - link 1 <- Trojan.Generic.KD, Win32/Zbot, W32/Cosmu
• McAfee Threat aliases for W32/Ramnit - link 2 <- SHeur3.AQRA, W32/Patched-I, Win32.Nimnul, W32/Pedalac

With this particular infection the safest solution and only sure way to remove it effectively is to reformat and reinstall the OS.

Why? The malware injects code in legitimate files similar to the Virut virus and in many cases the infected files (which could number in the thousands) cannot be disinfected properly by your anti-virus. When disinfection is attempted, the files often become corrupted and the system may become unstable or irreparable. The longer Ramnit.A remains on a computer, the more files it infects and corrupts so the degree of damage can vary.

Ramnit is commonly spread via a flash drive (usb, pen, thumb, jump) infection where it copies Worm:Win32/Ramnit.A with a random file name. The infection is often contracted by visiting remote, crack and keygen sites. These type of sites are infested with a smörgåsbord of malware and a major source of system infection.

In my opinion, Ramnit is not effectively disinfectable, so your best option is to perform a full reformat as there is no guarantee this infection can be completely removed. In most instances it may have caused so much damage to your system files that it cannot be completely cleaned or repaired. Security vendors that claim to be able to remove file infectors cannot guarantee that all traces of it will be removed as they may not find all the remnants. If something goes awry during the malware removal process there is always a risk the computer may become unstable or unbootable and you could loose access to all your data.

Further, your machine has likely been compromised by the backdoor Trojan and there is no way to be sure the computer can ever be trusted again. It is dangerous and incorrect to assume the computer is secure even if your anti-virus reports that the malware appears to have been removed.

Many experts in the security community believe that once infected with this type of malware, the best course of action is to wipe the drive clean, reformat and reinstall the OS. Please read:

• When should I re-format? How should I reinstall?
• Where to draw the line? When to recommend a format and reinstall?

Whenever a system has been compromised by a backdoor payload, it is impossible to know if or how much the backdoor has been used to affect your system...There are only a few ways to return a compromised system to a confident security configuration. These include:
• Reimaging the system
• Restoring the entire system using a full system backup from before the backdoor infection
• Reformatting and reinstalling the system

Backdoors and What They Mean to You

This is what Jesper M. Johansson at Microsoft TechNet has to say: Help: I Got Hacked. Now What Do I Do?.

The only way to clean a compromised system is to flatten and rebuild. That’s right. If you have a system that has been completely compromised, the only thing you can do is to flatten the system (reformat the system disk) and rebuild it from scratch (reinstall Windows and your applications).

I was afraid of that answer...does this mean that even if different anti-virus are not detecting the virus anymore it's still possible that the PC is infected?...

Thanks a lot!
Catarina P

Hi Catarina, I hate to make that post.
Yes, it may remain hidden until it is again triggered by something.. Also remeber this part. with out a full reformat as there is no guarantee this infection can be completely removed.

Most important is the backdoor functionality. Your machine has likely been compromised by the backdoor Trojan and there is no way to be sure the computer can ever be trusted again. It is dangerous and incorrect to assume the computer is secure even if your anti-virus reports that the malware appears to have been removed.

This functionality allows hackers to remotely control your computer, steal critical system information and download and execute files.

I would counsel you to disconnect this PC from the Internet immediately. If you do any banking or other financial transactions on the PC or if it should contain any other sensitive information, please get to a known clean computer and change all passwords where applicable, and it would be wise to contact those same financial institutions to apprise them of your situation.

Thanks a lot for your feedback! I will format the computer then.
Keep up with the good work!

Catarina

You're again welcome. Here's some format info our quietman7 had put together.

Caution: If you are considering backing up data and reformatting, keep in mind, with a Virut infection, there is always a chance of backed up data reinfecting your system. If the data is that important to you, then you can try to salvage some of it but there is no guarantee so be forewarned that you may have to start over again afterwards if reinfected by attempting to recover your data. Only back up your important documents, personal data files, photos to a CD or DVD drive, not a flash drive or external hard drive as they may become compromised in the process. The safest practice is not to backup any executable files (*.exe), screensavers (*.scr), autorun (.ini) or script files (.php, .asp, .htm, .html, .xml ) files because they may be infected by malware. Avoid backing up compressed files (.zip, .cab, .rar) that have executables inside them as some types of malware can penetrate compressed files and infect the .exe files within them. Other types of malware may even disguise itself by hiding a file extension or adding to the existing extension as shown here (click Figure 1 to enlarge) so be sure you look closely at the full file name. If you cannot see the file extension, you may need to reconfigure Windows to show file name extensions. Then make sure you scan the backed up data with your anti-virus prior to to copying it back to your hard drive.

If your CD/DVD drive is unusable, another word of caution if you are considering backing up to an external usb hard drive as your only alternative. External drives are more susceptible to infection and can become compromised in the process of backing up data. I'm not saying you should not try using such devices but I want to make you aware of all your options and associated risks so you can make an informed decision if its worth that risk.

• How and Where to backup your files in XP or Vista
• How to Backup and Restore in Windows 7
• How to use Ubuntu Live CD to Backup Files from your dead Windows Computer

Again, do not back up any files with the following file extensions: exe, .scr, .ini, .htm, .html, .php, .asp, .xml, .zip, .rar, .cab as they may be infected.

If you're not sure how to reformat or need help with reformatting, please review:

• How to partition and format a hard disk in Windows XP
• Prepping for a Clean Install Windows XP.

These links include step-by-step instructions with screenshots:

• XP Clean Install Interactive Setup
• How to reformat your computer in case of a severe malware infection
• Reformat & Clean Install Windows XP

Vista users can refer to these instructions:

• Windows Vista Clean Install
• How to Do a Clean Install and Setup with a Full Version of Vista
• How to Do a Clean Install with a Upgrade Version of Vista

Don't forget you will have to go to Microsoft Update and apply all Windows security patches after reformatting.

Note: If you're using an IBM, Sony, HP, Compaq or Dell machine, you may not have an original XP CD Disk. By policy Microsoft no longer allows OEM manufactures to include the original Windows XP CD-ROM on computers sold with Windows preinstalled. Instead, most computers manufactured and sold by OEM vendors come with a vendor-specific Recovery Disk or Recovery Partition for performing a clean "factory restore" that will reformat your hard drive, remove all data and restore the computer to the state it was in when you first purchased it. See Technology Advisory Recovery Media. If the recovery partition has become infected, you will need to contact the manufacturer, explain what happened and ask them to send full recovery disks to use instead..

If you need additional assistance with reformatting or partitioning, you can start a new topic in the Operating Systems Subforums forum.