Tuesday, September 21, 2010

How to remove computer viruses manually??

While installing a new software, while downloading a file from the internet , while plugging a USB device , while opening a malicious website and adding numerous other while's ...what we fear the most is --"does it have a virus"?
Probably its the most scary term for the computer users around the globe and every computer user has some way or the other encountered with it. We install numerous anti viruses to protect our systems but still we find ourselves in trouble numerous times. I myself have to tackle with them almost every week.
Its important to know that no anti virus can give you full protection so until you yourself dont knw some defences you cannot keep yourself safe.
We relay so much on our anti viruses but we hardly know that these anti viruses have so many loop holes that present virus designers are now targeting to infect the computer systems.
Let me give you an example, i personally use Kaspersky  anti virus and i recently discovered a loop hole in it that when the updater is updating the anti virus database from the internet then the scanner stops scanning the files until the download process is not complete. Even though it was the best antivirus of 2009 still it had such a major loophole. I mailed to the Kspersky labs about this bug and it got fixed in the next virus update definition.
There can be numerous other such loopholes that may exist and can be exploited so we must know some other countermeasures too.
Let me first give you some brief knowledge about computer viruses.

Vital Information Resource Under Seize .
 Computer viruses are small software programs that are designed to spread from one computer to another and to interfere with computer operation.A virus might corrupt or delete data on your computer, use your e-mail program to spread itself to other computers, or even erase everything on your hard disk.Computer viruses are often spread by attachments in e-mail messages or instant messaging messages. That is why it is essential that you never open e-mail attachments unless you know who it's from and you are expecting it.
Viruses can be disguised as attachments of funny images, greeting cards, or audio and video files. Computer viruses also spread through downloads on the Internet. They can be hidden in illicit software or other files or programs you might download.They can exist in numerous forms like backdoors, worms , trojans ,rootkits etc.

Indication of Virus:

1. When you plugin a drive, Some Autoplay feature polls you to select a option. If you see a folder like icon that reads open using the program provided on the device. Does not select that. Also does not select Open folder to view files using Windows Explorer. Since the virus can execute with these options. Cancel it.
Note: Windows 7 has disabled the autorun Option for flash drives since the autorun source is usually unknown.
How to Manually Remove Virus From USB Flash Drive without Formatting
2. You will also see a folder like icon instead of Flash Drive Icon in my computer
How to Manually Remove Virus From USB Flash Drive without Formatting

Removal of Virus from flash drives without running them:

1. In Start Menu Click RUN and then type cmd. Type your Flash Drive Letter followed with colon. Here
type attrib -r -a -s -h *.* and press enter.
This will unhide all files.

2.  Correct Way of Opening Flash Drives

Note: Do not open the Flash Drive by double clicking the icon in my Computer or By Right clicking and then Open,Explorer
Open the USB drive by using Folders Icon. How to Manually Remove Virus From USB Flash Drive without Formatting
Click on the Folders icon then select your Flash Drive
How to Manually Remove Virus From USB Flash Drive without Formatting
You can select Your Flash Drive by using the Address Bar in Windows Explorer.
How to Manually Remove Virus From USB Flash Drive without Formatting
Type your Drive letter in the Address Bar
How to Manually Remove Virus From USB Flash Drive without Formatting
3. After Opening the drive. Select Details View using this icon How to Manually Remove Virus From USB Flash Drive without Formatting

You can now see what the virus does with your Flash Drive. The Virus does disguises itself as folder. You can see that system file icon as illustrated here is similar to folder icon. You actually click on the file.
Actually you click on those virus file thinking of them as folder and the virus executes. In the detailed view you can clearly see that the system file has a Type description of application and the system folder has a Type description of Folder.
Delete all such files. Carefully do not delete the folders.
4. Delete the Autorun.inf file
How to Manually Remove Virus From USB Flash Drive without Formatting
5. You can also delete these files using 7-ZIP. Since it shows such virus files as havingapplication file icon.

Removing virus from the hard drive:
there can be no fixed way to remove a virus from the hard disk. Depending on the nature of the viruses the processes may change. Check your task manager to see if any malicious task is running or not, if you find any such task then locate its installed directory by right clicking on the selected task.
Dont delete it. Restart your computer in Safe mode and then go to that location to delete that file.
ARE YOU DONE?  Not yet you still need to delete the registries that have been modified by the virus. Go to the start menu, click on run , type there regedit.
You might be unable to RegEdit, because the virus blocks the doorway. In this case, you need to bring up your Windows in Safe Mode to run the RegEdit. Sometimes, you need to login the Administrator account. Therefore, make sure you know your Administrator account's password when you own the new computer.
Microsoft System Configuration Utility MSConfig.exe keeps entries of Start-Up programs. Besides that, System Registry has RunRunOnce and RunOnceEx entry nodes to manage which program can run while Windows is starting.
First, you should check any starting programs inside the HEKY_LOCAL_MACHINE.
Go down to the node in HEKY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion, then look for program entry inside the Run, RunOnce and RunOnceEX. If you find something you don't know, then you type the program name .exe name into the following Search box to find out what's that. If the .exe name is the virus or spyware, then you can delete it.
It's same that you need to check any starting program inside the HEKY_CURRENT_USER.

Go down to the node in HEKY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion, then look for unwanted .exe programs inside the Run, RunOnce and RunOnceEX. If you find something, then delete them.
Some virus will restore the entry later or reboot, even you delete the entry from System Registry Editor. Those virus needs special tools to kill them.

The problem arises when you cannot find the application runing in the task manager. To remove such viruses you need to unhide all the hidden files and folders and then manually make a search in the c:\windows folder .
Then reboot your computer in safe mode . Then run msconfig.exe. Search for the malicious application running at startup. Unmark it and reboot your computer . Check weather the problem now persists or not.
There are different levels at which we can tackle with viruses manually. These are just an overviews of what can be done. You can search for lot more hidden ways to eliminate viruses manually.

Strange as it may sound, the computer virus is something of an Information Age marvel. On one hand, viruses show us how vulnerable we are -- a properly engineered virus can have a devastating effect, disrupting productivity and doing billions of dollars in damages. On the other hand, they show us how sophisticated and interconnected human beings have become.
Thanks for reading.Comments and critics are always welcome.