This is not good news, especially since it seems this infection has been running rampant for a while now considering the number of infected files ESET found:
Win32/Ramnit (and related variants) 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 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. 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.
- 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
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. However, a variant called the Ramnit worm targets Facebook users....can bypass two-factor authentication and transaction signing systems, gain remote access to financial institutions and compromise online banking.
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:Backdoors and What They Mean to You
This is what security expert miekiemoes has to say: Virut and other File infectors - Throwing in the Towel?
This is what Jesper M. Johansson at Microsoft TechNet has to say: Help: I Got Hacked. Now What Do I Do?.
Edited by xXToffeeXx, 18 January 2014 - 10:07 AM.
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