Most of times virus spread via external drives like pen drives
or external hard disks compare to online.
Here we see how to detect the virus in your system.
Always Disable Autorun
Autorun is a function of your
operating system which makes your external drive able to do something when it
is connected to your system. Virus creates a file on external drive named
‘autorun.inf’ and put instructions in this file to execute itself automatically
when the drive is connected. When you connect your external drive, system takes
instruction from ‘autorun.inf’ on the drive and executes them. So virus gets
executed and affects your system.
So disable the “autorun’
function. You can do it from ‘group policy option’ or from ‘registry’.
If you don’t want to disable it then you can
hold shift key on your keyboard while you are connecting your external drive to
your system. By holding shift the autorun.inf file on your external drive will
not be automatically executed.
Show Hidden & System Files
Go to Control Panel -> Folder
Options -> View tab. Uncheck ”hide extension of file” option, means you
should always know that what is the extension of file that you are
accessing. Then check “show hidden files” option and uncheck “hide system
files” option
(This will help you if virus has
not affected your system yet. if your system is already affected then maybe
this option won’t work, I mean the folder options settings will be reset every
time automatically.)
Check Whether Your System Is Infected
If your external drive is
affected then probably there is a autorun.inf file looking like hidden and
system file. Try to delete it normally. If it’s get deleted then it will be
easy, and if not then go to its properties and uncheck hidden and read only,
then open it in notepad and remove everything and save it, or just delete file.
If still not working or error
occurred that ‘access denied or read only file’ then
Close file and start CMD (Press
‘Win’+'R’, type ‘cmd’, press enter).
Now go to your drive (suppose it’s
‘f’ then)
Type f: and press Enter
Now change the attribute of
autorun.inf file by typing
attrib -h -s -r “autorun.inf”
(h for hidden, s for system and,
r for read only)
Now you can delete it by typing
del “autorun.inf”
Or just open your drive and
delete it. It will get deleted (in 99% case).
(You can use dir/ah command to
find files)
Now delete all the suspicious
file in drive, like ‘looking like a folder but with .exe extention’ or any
suspicious file with size 67kb or 128kb or 2kb… any file which you found
suspicious can be deleted after you delete autorun.inf file.
If Your System Is Already
Affected
Well there is many things you
can do to make it good from worst.
So there is much kind of
symptoms, like
·
cmd (not able to start)
· Task Manager (not able to start
· Folder Option (get reset every time)
· Registry (not able to start)
·
msconfig (not able to start)
Now what to do to make those works..
So here are some steps that you
can try
1. Start system in safe mode. (work in most cases)
2. If safe mode isn’t working then try to use safe mode with cmd
prompt.
3. Create a new user and check in that new user account if cmd can
be open or not.
4. Always keep some software (like tune up utilities) from which
you can check date of any service created. Use one of them and start cmd any
how.
Now, after you are able to start
them.
· First start task manager (CTRL+SHIFT+ESCAPE) and end all
suspicious services.
· Then end explorer.exe also
· From new task start msconfig.
· In msconfig go to service tab and uncheck any suspicious or
unwanted service. You can guess by manufacture or by thinking that did you have
installed something related to that service or not.
· Go to startup tab. check for service which look unknown or cross
check with tune up ( on which date service is created) or any service that you
can say its virus.
· Check location of that service from where it is started, you can
find location within startup tab under COMMAND. it will show you the path of
the file
· Again open cmd.
· Go to that location.
· Change attribute of the file.
· DELETE it
· Do it for every file that look like virus to you. Be care full,
you will need some experience, because if you delete some important file then
it can cause problem in related application.
Let’s talk about different
problem
Sometimes a problem arise, that
you can’t open anything, everything get opened in media player or notepad or
office, or something else. Even in safe mode you can’t open any exe file.
What will you do then? Don’t worry, mostly this type of virus only attack
specific user. You can repair this by creating a new user. But Control panel
and user account won’t work in this case.
1. Just go to manage (My computer–> right click–> manage)
2. Now local user and group–> User–> right click in blank
space and select create user
3. Put user in administrator group.
4. Now logoff and login to new user.
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