My nephew said if my computer is plugged into the internet hackers can still access my information is this true?

[Pleasant]

weather or not my computer is turned on or not

[Daniel]

Short and simple: yes and no. Yes to your question, but no to the extra info you provided. Your computer MUST be turned on for anyone, hacker or even yourself, to access any data on the machine. If your computer is on and connected to the internet (WiFi or cable), it is potentially susceptible to infection. That being said, if your computer is sitting there and you aren't using the internet, I wouldn't worry much because of your antivirus. Your computer has a bare minimal protection that helps to protect from prying eyes but I would invest in a good antivirus. I myself like AVG or Bitdefender. But those are personal preferences.

As always, if you are online, practice safe browsing. Don't click links in your email, open up the proper link manually (especially financial or similar emails) and don't click ads. You know, basic stuff.

[KnightSaber2000]

If the computer is switched off, it is not true..
Although some motherboards do have this feature, to switch on automatically on Network command.. but you need to activate that manually first in order for that to work, which is very unlikely, unless a spy have sneaked in and manually activated that feature in the BIOS setup..

When your computer is on, yes it is very likely..
The general wisdom dictates:
• Purchase the best antivirus software in the market (like Norton, Kaspersky and McAfee, and never the free antiviruses) and make sure it is regularly updated..
• make sure your Windows (or any operating system) has the latest update.. as companies like Microsoft, often send updates to block hackers and malware attacks to the windows operating system..
It is worth to note that Microsoft will officially cut its support to Windows XP this week.. so if you are still using windows XP, you maybe prone to the next big attack on your system.. and you may need to migrate to the next windows system, like Windows 7 and 8 that is still very much under Microsoft's support..
• never download something from untrusted source, like email attachments..
• never click on a link to an unknown destination or from a complete strangers..
• never visit Porn and online gambling sites, they are notorious for being the favorite sites for scams and hackers, as credit card information are frequently shared at those sites..
• make sure your WIFI is password protected (that meets WPA standards and none of the WEP stuff)..
• make sure that your passwords are long and difficult.. do not use "password" for your password.. make it complex with numbers and symbols if possible..
• when accessing your accounts: your online bank account, your Facebook, yahoo, Google account etc.. try to avoid cybercafé computers.. or use WIFI from an unknown source..
• when possible, minimize sharing with older computers (or with other computers) via portable hard disks and thumb drives.. many of thumb drives shared between my friends, have raised red flags by my antivirus program as being infected..
• Visit the Windows Firewall and the antivirus Firewall software, and block the connection of a software to internet.. you see, every program that tries to access the internet must request an internet access, Firewalls are basically a major obstruction that prevents internet flow unless to those programs that is authorized to..
When you open the firewall program, you should see a list of programs that is trying to access the internet with words like (allowed, limited and blocked) next to it..

Your browser, like the internet explorer and Firefox should have the "Allowed" option next to them.. but be in a look put for software with obscure names like "FreeAds" or "A Better Internet" and block them..
Usually, windows and the antivirus program have the nose for those things, but they often ask the user whether this software is reliable.. most often we answer yes, while it should be No..

Most computer viruses or malwares are aimed to steal personal information, like you social security number, your credit/debit card information.. Long has gone the time when computer viruses were simply search and destroy programs..

whenever possible, never share those personal information online..

If you are a frequent internet shopper at eBay and such, you can create another bank account with its debit card, and deposits a few amount of money each time (few hundred bucks each time).. and you can use that debit card for online purchase..

If a computer hacker or a computer virus somehow gained access to those private information.. only few bucks would be lost, compared to life savings on the main bank account..

All the best

[Shahrukh]

Yes and no!

If your computer is switched off then hacker can't access your data but if hacker copy your all data then he can format your hard drive !
So if something like happening then buy anti virus like avast or quick heal get latest s/w update !

[DunbarPappy®ϟϟ]

I will go somewhat against prevailing answers, and say that if your router is one of the many with poor security (sometimes a default firmware condition) which permits either a remote Internet connection , or local WiFi access to the Admin. (called "LAN Access");
Or your system is connected directly to your modem with no router;
And/or you have configured the system to permit 'Wake on LAN';
And/or your system allows "Remote Access";
then there are conditions where it could happen.

Good security is a blend of many fields and adhering to 'best current practices', which the average home user is oblivious to.
When in doubt about your ability to control all these conditions, take the following precautionary steps:
Connect your modem and router to a 'power strip', and turn that "Off" every night by the switch.
Re-power when needed. It should make the necessary "iP resolution" automatically.
Now you have removed all doubt.

[Minister of Truth]

highly unlikely.

would they hack your pw that,s prob a higher level of encryption like wpa2-psk?

a strong pw has #s, caps, l.case and special characters like @ &, etc.

all that,d take hours.

they have much more "productive" things to do.

my win7 lap is almost always on in Sleep, etc., and "connected" to the net.

but after a certain time of inactivity, my isp sometimes logs me off, and pw is necc to get back on net.

I have only Microsoft Security Essentials: firewall, anti vir & anti adware.

MSE updates almost daily.

In windows, review Windows Updates daily.