My PC got infected with a w32.virut virus
Your system is infected with a nasty variant of
Virut, a
polymorphic file infector with
IRCBot functionality which
infects .exe, .scr 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.
-- 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.
According to this
Norman White Paper Assessment of W32/Virut, some variants can infect the
HOSTS file and block access to security related web sites. Other variants of virut can even penetrate and infect .exe files within compressed files (.zip, .cab, rar). The
Virux and
Win32/Virut.17408 variants are an even more complex file infectors which can embed an iframe into the body of web-related files and infect script files (.php, .asp, .htm, .html, .xml). When Virut creates infected files, it also creates non-functional files that are corrupted beyond repair and in some instances can disable Windows File Protection. In many cases the infected files
cannot be disinfected properly by your anti-virus. When disinfection is attempted, the files become corrupted and the system may become
irreparable. The longer virut remains on a computer, the more critical system files will become infected and corrupt so the degree of infection can vary.
The virus disables Windows File Protection by injecting code into the "winlogon.exe" process that patches system code in memory.
CA Virus detail of W32/Virut
The virus has a number of bugs in its code, and as a result it may misinfect a proportion of executable files....some W32/Virut.h infections are corrupted beyond repair.
McAfee Risk Assessment and Overview of W32/Virut
There are bugs in the viral code. When the virus produces infected files, it also creates non-functional files that also contain the virus...Due to the damaged caused to files by virut it's possible to find repaired but corrupted files. They became corrupted by the incorrect writing of the viral code during the process of infection. undetected, corrupted files (possibly still containing part of the viral code) can also be found. this is caused by incorrectly written and non-function viral code present in these files.
AVG Overview of W32/Virut
Virut is
commonly spread via a
flash drive (usb, pen, thumb, jump)
infection using
RUNDLL32.EXE and other malicious files. It 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.
...warez and crack web pages are being used by cybercriminals as download sites for malware related to VIRUT and VIRUX. Searches for serial numbers, cracks, and even antivirus products like Trend Micro yield malcodes that come in the form of executables or self-extracting files...quick links in these sites also lead to malicious files. Ads and banners are also infection vectors...
Keygen and Crack Sites Distribute VIRUX and FakeAV
However, the
CA Security Advisor Research Blog have found
MySpace user pages carrying the malicious Virut URL. Either way you can end up with a computer system so
badly damaged that recovery is not possible and it cannot be repaired. When that happens there is nothing you can do besides
reformatting and reinstalling the OS.
Since
virut is not effectively disinfectable, 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. In many cases the infected files (which can number in the thousands)
cannot be deleted and anti-malware scanners cannot disinfect them properly. 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 reformat and reinstall the OS. Reinstalling Windows without first wiping the entire hard drive with a repartition and/or format will not remove the infection. The reinstall will only overwrite the Windows files. Any malware on the system will still be there afterwards. Please read:
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).
Important Note:: If your computer was used for online banking, has credit card information or other sensitive data on it, you should disconnect from the Internet until your system is cleaned.
All passwords should be changed immediately to to include those used for banking, email, eBay, paypal and any online activities which require a username and password. You should
consider them to be compromised. You should change each password using a clean computer and not the infected one. If not, an attacker may get the new passwords and transaction information. Banking and credit card institutions should be notified of the possible security breach. Failure to notify your financial institution and local law enforcement can result in
refusal to reimburse funds lost due to fraud or similar criminal activity.
