Introduction to digital security

for Windows users

by Alan Zisman (c) 2017-2023:

These notes:
Ukrainian translation
last updated 2023-10-22

It's a jungle out there - instead of lions and tigers and bears there is spam and ransomware and malware. All you want to do is to go online to communicate with your family and friends, get the news and other information, maybe look at some videos or listen to some music. And it feels like you risk being mugged - or at least getting your computer hijacked by someone who wants you to send them money to set it free. And senior citizens are especially being targetted - partly because they often don't have the information or the experience online to know how to protect themselves.

You'd like to do the right thing, but advice can be contradictory or difficult to follow. No wonder an October 2016 article from computer security company Sophos headlined: ‘Security fatigue’ leading computer users to more or less just give up.

Don't give up!

There are a few things you can do to make your computer more secure and your online experiences safer without driving yourself crazy - but just as you've probably learned what makes a street look a bit sketchy and how to keep yourself personally secure you have to learn to look out for warning signs that an email, website, file attachment, or download is a bit sketchy and what to do if you can't avoid it.

Note that this workshop is aimed at Windows users - as the most widely used desktop and laptop computer platform, Microsoft Windows and its users are the most targetted. Users of Apple Macintosh computers and iPhone/iPad (iOS) and Android mobile devices also should think about digital security, and while some of the suggestions made here will also apply to them, they should look elsewhere for specific advice: Mac malware: Coming soon to a computer near you and The Ultimate Mac Security Guide: 20 Ways to Protect Yourself

As well note that there is always a balance between security and convenience. Having multiple locks on your front door may make your home more secure but it will take longer to open the door every time you come home - and someone with a fire axe can still bust your door in. You'll never be 100% secure online - the trick is to find a balance between security and convenience that keeps you pretty safe while still letting you do what you want to do.

Some general suggestions:
Notice that many of these scams and frauds don't involve infecting your computer with anything - they consist of convincing you to voluntarily give away bank account or other log-in information. Those that do involve infecting your computer often work by tempting you or scaring you into clicking on a link or installing bogus software. This is called 'social engineering' - it's not really using technology, it's using psychology to trick you into giving them information or infecting your computer. If I phone you and ask for your password, hopefully you won't just give it to me. If I phone you and claim to be from your Internet service provider, you're more likely to give out your password.

Vocabulary to know:
(Most definitions from

Your first line of defense - see through fraudulent links and addresses

Naughty Neighbour email reveals linkThe first problem is that often online - both on a web page and in an email message - you can't easily tell where clicking on a link will take you. Just because something on a webpage or in an email message says it goes to (say) TD Bank doesn't mean it really goes to that bank. Even if the text looks like it's a web address: it could actually point somewhere else - in both cases, these links go to my website:

 You can see where a link is pointing by letting your mouse hover on the link without clicking. Most current web browsers - the program you are using to access web pages - has that option enabled. Try it - point to the underlined boldface words in the preceeding paragraph. Do you see a web address (URL) - perhaps in small print in the lower-left corner of your web browser? (If you are using an older version of the web browser, you may need to enable the 'status bar' if you're not seeing seeing the real address hiding behind a link).

When you hover your mouse pointer over a link examine the web address that now appears in the bottom-left of your web browser. If you are hovering over a link that claims it will take you to the TD Bank and instead it takes you to you should be suspicious. Even if it looks like the place you want to go is embedded in the middle of a long link, you should be suspicious. For instance, further down the bogus Bank of Montreal email pictured above was a link - it read:  Confirm and verify my account but it pointed to a link reading - not the real Bank of Montreal web address, (But it included 'login-bmo' to try to look legitimate).

Clicking on this link opens up a PDF version of an email that my friend Jane sent me - it claimed to be from Apple, noting an attempt to sign into iMessage that might have been bogus. There are several hints that this email is phony - near the top, it reads: From: Apple [] - Apple would almost certainly not send email from an account named ''. That however, could be controlled by a more sophisticated scammer. Further down, there's a warning in bright red, added automatically by Gmail. It tells us that the link claiming to be '' actually points to a very different web address, with a '.ru' domain meaning it's somewhere in Russia. Even without that warning, hovering the mouse over the link (without clicking it!) would show the actual address where that link points. (Note that none of the links exist in this PDF version of the email - hovering your mouse over them won't show anything!)

Know a little bit about file types and the three-letter extensions at the ends of file names (often hidden) - many bogus 'naughty neighbour' email messages include a link promising to get you in touch with someone in your neighbourhood who's anxious to meet you. Typically, hovering my mouse over these links shows me something including the 3-letter extension 'php'. That's the file extension for web-based programs - not a photo, not a video clip, not a traditional link but probably a program looking to infect my computer. (Remember - "if it's too good to be true....") Don't click!

Many email programs do something similar - for instance, in the Windows 10 Mail app, hovering my mouse over a link in the legitimate email from local organic food delivery service SPUD popped up the address of the link - note that it appears to be legitimately at the company's website: - as it should be! Legitimate web addresses will have the text you expect to see near the beginning of the link, not somewhere in the middle or at the end.

Windows 10's Mail app

Make sure that your web browser and email software allow you to see where a link is really pointing - start using this feature and learn to tell whether a link looks legitimate or not.

Just as links can be bogus, you may receive emails pretending to be from people you know. Here's one I received that claimed to be from my friend David (last name whited out).

Fake email from a friendThe text is pretty generic - what's the link pointing to? Why would I enjoy it? Hovering over the link gives me the same address that appears in the email's text - but look at the email address beside David's name - not an address I would expect him to have! Sometimes your email software may hide the address of people who appear to be in your contact list, but hovering your mouse will make it appear if you're suspicious - or clicking on the name. See how you can make the address appear in the program that you use for email. In the Windows 10 Mail app, for instance, double-clicking the sender's name opens up a box that includes the address used to send the message.

How did this happen? Apparently, some time in the past David's email address book was hijacked - this might have involved his computer getting infect but might also have been the result of a breach at his email service. (For instance, over 500 million Yahoo email users accounts were breached with details becoming known in 2016 - see: Recognize and secure a hacked Yahoo Mail account

Note: even if the email had shown David's real email address, it still might have been - and in this case would have been - bogus, wanting me to go to that suspicious-looking web link.

More: see - Phishing: Would you fall for one of these scam emails?  and Can you pass Google's (2019) Phishing Quiz

Second line of defense - your passwords and PINs

Many of these scam emails are trying to trick you into going to a bogus website that looks like the log-in page for a bank or online service where you do business - when you try to log in, they'll have your login name and password or personal identification number. Then they can use these to log in as you and potentially empty your bank account or purchase merchandise and have it be charged to your account or....

If you suspect one or more of your accounts has been breached, the first thing you should do is log into the real site and change your password. The sooner you do that, the better.

Passwords, however, can be a problem for a lot of people - many people are overwhelmed by having too many passwords or use a single password for everything and/or use a simple, easily guessed password. ('1234', 'abcd', 'qwerty', 'password', etc).

You've probably heard the advice about having complicated passwords that mix text with numbers (and optionally symbols) and to use a different passwords for each account - the advice is overwhelming and the results are almost impossible to remember. Moreover, our computers offer to remember our passwords - handy, but with the result that if you have to log in on a different computer or device (or using a different web browser on the same computer) you may not remember the password that you used. (Google Chrome and Mozilla Firefox web browsers let users to create accounts and then save all their passwords online in their account; logging in to that account on a different computer or device gives access to all the saved passwords. Similarly, Apple customers can save passwords to Apple's iCloud - making them available when they're logged into any Mac, iPhone, or iPad).

There are a several ways to deal with password/PIN overload. Among them:
Many services (Facebook, Gmail, Microsoft, etc) offer a security option - often referred to as two-factor authentication or two-step verification. When you set it up, you're - to provide an extra level of security - asked for a cell phone number or email address. Afterwards, if someone - even you - try to log into your account from a device that's never been used before with that account a text message or email is sent out with a code number. Before the new log in can successfully connect, they need to enter that code number.

This ensures that the log in is really from you, since it's unlikely that the person using your stolen password also has your cell phone.

It can be a bit of a hassle, though, when the new user is actually you - using your brand new device, for instance, or logging in on a friend's computer. Maybe the added security is worth it. More info:

Here is information on adding two-factor authentication for: 
See: How to set up two-factor authentication

Taking two-step authentication to the next level. There can be problems getting codes sent as text messages when needed. For instance, when I'm travelling, I often get a foreign SIM for my phone. When I do that, I won't receive text messages sent to my Canadian phone number. Better may be to use codes generated by an app. The Facebook mobile app inclused a 'Code Generator' function for this. Google now has a Google Authenticator app for Android and iOS. After installing it on your phone and setting up your Google security settings to validate the app, you'll get codes as needed through Authenticator - no text messages needed - you can even use the Google Authenticator app to get codes for Facebook or other non-Google accounts. (One limitation - if you get a new phone, you'll need to move Authenticator from the old phone to the new one in order to generate valid codes).

See: Everything you’ve been told about passwords is a lie

Third line of defense: Security Software

In addition to learning to recognize scams in email and on websites and using good passwords, every Windows users should be running some sort of security software. Recent versions of Windows comes with free basic security software - a firewall (to block unauthorized access through the Internet to your computer) and anti-virus software named either Windows Defender or Microsoft Security Essentials. When you log into Windows for the first time, you'll get a notification if these are not enabled.

The firewall is basic but okay - there's probably no need to get additional free or commercial firewall software. (These may include options useful to families wanting to restrict when and when their children go online). Windows Defender and Microsoft Security Essentials - built into recent Windows versions - have gotten much better and may be all you need.. Recognizing that, many PC manufacturers include a trial version to a more effective commercial security program. (They receive money to do that from the security vendor). While more effective, note that these packages are trial versions - they typically work for between one and three months before they need to be purchased - usually with an annual fee. And if you don't pay the fee, they will no longer update themselves - and an out of date security program quickly becomes less and less useful, even if the computer owner thinks they're being protected.

Alternatively, one of the free packages recommended in PC Magazines annual The Best Free Antivirus Protection review does the trick - look for the products identified with [EC] for 'Editor's Choice'. Each will try to up-sell you to their paid version and will pop up ads and reminders to help make that point. If you can live with the nagging, the free version will do the job. Just be prepared to let your anti-virus/security software update itself on a regular basis. (In 2016, PC Magazine rated Avast, AVG, and Panda the best free anti-virus programs. Here's PC Magazine's annual guide to The Best Antivirus Protection (non-free). In 2016, their winners were McAfee, Webroot, Bitdefender, Kaspersky and Symantec/Norton. On my Windows system, I uninstalled the free Avast because I found their frequent pop-ups to sell paid services annoying, and reverted to Windows 10's built-in Windows Defender.

Note however the contrarian: You Don't Really Need an Anti-Virus App Anymore

('Classic' computer viruses are rare these days; according to PC Magazine,  "ransomware and data-stealing Trojans are much more common, as are bots that let the bot-herder rent out your computer for nefarious purposes." Modern 'anti-virus' software tries to protect your computer from a wide range of malware - not jut computer viruses).

However - even with good, up-to-date security software running in the background, your computer may still become infected. Maybe you clicked on an ad on a website or a pop-up message that claimed that your computer was infected, and in the process download a program that infected your computer.

If you're not sure , see: 10 Signs Your Computer Is Infected With A Virus and 7 Signs You've Got Malware and How to Remove Malware From Your PC

Back up your anti-virus/security program with MalwareBytes - again it comes in free and paid versions. The free version does a great job of cleaning up an already infected computer. In order to get the latest version, you may want to get it when you think your computer has been infected - download it using a different, uninfected computer if possible, copy the installer onto a USB memory stick and install it onto your infected computer. Then start it up and let it do it's thing. Maybe run it several times - restarting your computer after each run - until you get a report that your is clean.

Note: Some security software is bogus - especially programs that want you to purchase them after popping up messages claiming your computer is infected. Are you running any of the programs listed in: This Security Software Is Insecure! 5 Tools You Should Get Rid Of (Hint: the 5 programs listed are: Mac Defender, Security Essentials 2010 (not Microsoft Security Essentials), MS Antivirus (not from Microsoft) - aka ANG Antivirus, XP Antivirus, Total Security, PC Defender Plus, AVASoft Professional Antivirus, Privacy Center - aka Safety Center, Privacy Components, and WinFixer. These programs, claiming to be security software, are in fact malware.

Windows 10 users may simply stick with the version of Windows Defender built into Microsoft's latest operating system. See: 4 Reasons to Use Windows Defender in Windows 10

A free online virus scanner is offered by the retailer Best Buy together with anti-virus company Webroot.

About downloads and attachments: Downloads and email attachments can be malicious and infect your computer. Because of this, many people avoid all downloads and email attachments. That's safe, but on a par with never going in a car because sometimes there are car accidents. Better is to learn to recognize unwanted and potentially malicious email attachments and downloads, while taking advantage of safe, useful, and enjoyable attachments and downloads.

Downloads folder- Email attachments are files sent along with an email message (files can also be attached to text or Facebook messages). These files can be photos, short video clips, music files - all of which are generally harmless - or program files, which might be dangerous. The key questions are who is sending these and is it the sort of thing they usually do? I play in several bands - if I got music files attached in an email from someone I play music with, that's probably okay - especially if there was a note in the email talking about the tunes. (Here's a recording of Duke Ellington playing 'Caravan' - give it a listen; I'd like us to try to play this next Tuesday when we get together).

If I'm not sure, before opening the attachment I can fire up an email to the friend - creating a new email message, not replying to the possibly bogus one - asking if they really sent me an attachment. If they're puzzled, then I know it's bogus.

Note that email attachments are generally saved to your Downloads folder...

See: Don’t Be Fooled By This New “Helpful” Email Scam

- Downloads - you can download photos, videos, books and music files over the Internet, as well as programs. Many or most are harmless - though in some cases they may be being distributed in violation of copyright. There are lots of free programs legally distributed online - I've recommended several and included links in this page. To use them on your computer, you need to download the installation file and run it to install the program on your computer.

In some cases, though, downloaded programs can be malicious and install malware onto your computer. There are several ways this can happen:

-- as the result of clicking on a pop-up message warning that your computer is infected - remember, any such message is bogus unless it's from the anti-virus program that you know you installed. And that software won't pop up message on a website - the messages will typically show up in the lower-right corner of your screen whether your web browser is open or not.

-- searching for software - particularly searching for a free (or 'cracked') version of commercial/paid software and going to an unknown source for the program. If I'm looking for the malwarebytes anti-malware software, downloading it from or is where I want to go - google also shows me links to a variety of other download sites. Maybe they're reliable, but maybe they're trying to trick me into installing a piece of nastiness pretending to be the real software. As always online, it helps to know what's a reliable source. Trying to get software for free that's usually for sale is especially risky, but even searching for legitimately free programs can be problematic. Best is to go directly to the source!

-- searching for TV shows or movies can be risky if you're outside of a known site (like Again, you may get a real video file or you may not. Windows by default hides the final letters of a file name (the file extension) which identify what sort of file you're getting - this means that a program file (with a file extension .exe) can be easily disguised as a video file (with file extension .avi or .mov or .mp4). If you're not sure about a downloaded file you could open the Windows File Explorer, switch to Details View, look at your Downloads folder. The Details view has a Type column - if the file is identified as a movie, you're good to go.

Notice that in the image on the right, looking in my Downloads folder there are lots of Applications, a Microsoft Word Document, an MP3 (music) File, and several other file types listed.

See: Download me—Saying “yes” to the Web’s most dangerous search terms

Spam, phishing, porn and more: A decade or so ago, people's email inboxes were cluttered with unwanted and unrequested messages advertising products and soft-core porn. To a large extent these messages are no longer so visible - partly the result of legislation but more because of more effective spam filtering by email providers and built into email software.

Spam folder Most of our email accounts include a spam folder - if something that you think is spam  does land in your email in-box, you can send it to the spam folder - which may increase the accuracy of your spam filtering. Your spam filtering makes the opposite mistake as well, however.... flagging a legitimate message as spam and automatically putting it in the spam folder without showing it to you first. If you miss a message that you expect, check the spam folder. (For instance, while Google/Gmail's spam filtering is very good, it routinely puts messages from Amazon telling me that a package I ordered has shipped, in my spam folder).

So it's worth peeking into your spam folder from time to time - if you see messages there that you want, you should mark them as 'not spam' or move them to your in-box. On the right is some of the spam folder for my Gmail account. Note that Google automatically deletes any message that's over 30 days old in the spam folder.

Notice that some of the messages: Cunard Line, Fiat Canada for instance are from legitimate companies who have me on their email list. If I cared to read them, I might mark them as non-spam. Many of them appear to be porn - they're not. Instead, like the message claiming to be from 'Harriet Burke' near the beginning of this page, they include links to 'php' files that would probably install malware on my computer or try to steal my contact list or hijack my email software. The message claiming to be from BMO/Bank fo Montreal illustrated above was also in my spam folder. Much of what's in the spam folder isn't old-style harmless but irritating spam - instead it's email messages attempting to infect my computer or steal money.

If I open a message that's in my spam folder, Gmail doesn't let me see any of the questionable links - protecting me from clicking on them by mistake. If I move those messages back to my in-box, however, I'm no longer protected from my own stupidity. Still, moving an email from Amazon about a package that I know I ordered is pretty safe!

More: See: Don’t Be Fooled By This New “Helpful” Email Scam

The phone call from 'Microsoft Windows': Microsoft does not have employees checking server logs to identify computers that are infected, not does it contract out to other companies to do that. Any phone call that you receive telling you that your computer is infected is bogus - just as any message that pops up on your screen saying your computer is infected is bogus - unless it identifies itself as being from the anti-virus/security program that you have installed (and pops up as a standard Windows notification).

The phones were very common a few years ago and seemed to be targetting seniors in particular. The general process was for the caller to identify themselves as being from Microsoft (or from Windows or Microsoft Windows) and saying that they'd noticed from online logs that your computer was infected. If you didn't hang up immediately, they would claim that they could verify this - asking you to go to your computer and search for a particular filename - which would always appear to be on your computer (assuming it was a Windows computer - they named a standard Windows file).

Once you were convinced that your computer was infected, they might walk you through the process of installing remote access software - which is often used legitimately by tech support people to allow them to make changes to a remote computer. Once that was installed they could do what they wanted at your computer - often installing bogus anti-virus software. (They may at that point ask for a credit card number to pay for their 'service'.) Often, the installed program does nasty things to your system - malware or ransomware and requires that you pay to have it de-activated or removed.

See:  Microsoft's advice: Hang up on tech support scammers and We talked to Windows tech support scammers. Here's why you shouldn't and How to Discourage Windows Tech Support Scammers When They Call You

In a late-2016 twist on this scam, fake installers for Microsoft's Security Essentials software claims that your computer is infected and ask you to phone a number for help to get it cleaned up. See: Microsoft: Beware this fake Windows BSOD from tech support scammers' malware

In March 2017 there were reports of a hack of Apple's iCloud service - emails and phone calls claiming to be from Apple are equally bogus!

Sometimes if your computer has been infected with ransomware, you'll find that your computer's documents have been encrypted - and that only the people who infected your computer know the secret password needed to make them usable again.

In that case, the best thing you can do - best of a bad set of choices - may be to pay up and hope that the ransomware will be removed. Increasingly, ransomware has been targetting organizations like hospitals and schools - but individuals are still being targetted as well.

See: Why ransomware is booming in 2016 and Beat Scammers With These Ransomware Decryption Tools and Ransomware is about to get a lot worse, by holding your operating system hostage and Ransomware: A guide to one of the biggest menaces on the web and After WannaCry, Should You Worry About Ransomware?

Maybe it's not your fault - If your friends are getting emails claiming to be from you that you didn't send, it might be that your computer has been compromised. But it's more and more likely that it's not your fault - instead, an online service where you have an account may have been compromised. Why spend time trying to hack your computer when by hacking an online server you can get account information for tens of millions of accounts. For instance:
When you hear reports that an online service you use was compromised, go there directly (i.e. type the service's address in your web browser) and change your password. Don't trust emails claiming to be from the service asking you to click on a link to change your password - that could easily be a fraudulent link trying to steal your log-in info.

Instantly check whether your email address has been 'pwned' (i.e. compromised) at Have I Been Pwned
If you've got an Apple iCloud account, see: How to protect your Apple iCloud account

Worst-case scenario: one more reason you need a backup strategy!

Whenever you have a computer problem, tech support people will ask if you have a backup. Making backups means you have copies of your documents and programs and can use the backup copy if some sort of problem - anything from a physical hard drive crash to theft or other loss to software disaster like ransomware or virus - makes it impossible to use the original copy.

In a worst-case digital security situation, if you have a backup you - or tech support people - can restore your computer to its original out of the box condition, then restore your backup and get your computer back to the state it was in when you made your backup. You would only lose files created or changed since you made the backup. (This assumes that your backup wasn't infected with whatever infected your computer!)

Windows 10, for instance, includes System Restore and Factory Restore options as well as a built-in backup program.

Also see: If we show you how to back up your PC for free, will you finally do it?