In the previous video, you learned about dictionary attacks and how hackers use computer programs to automatically enter thousands of words from a dictionary as possible passwords.
In this video, you will learn how a hacker could use a dictionary attack to automatically create variations on the five-thousand most popular words in the English language in order to guess your password.
Hackers often choose to vary common words by adding: An S at the end to make the words plural, Symbols, Characters, Numbers, such as 123 or a house or apartment number, A birthdate, Or a birth year.
One of the most common variations hackers use is making a word plural.
So this first example adds an S to the end of each word.
You will use the concatenate function to add the S. Concatenate means to link things together.
To begin, return to your Dictionary Attack spreadsheet.
In the 5,000 words sheet, click inside cell B one.
Type an equals sign to start your function.
Then type the word concatenate.
Select it from the autocomplete menu.
After the open parenthesis, reference cell A one.
Type a comma and a quotation mark.
Then, type the variation you chose -- in this case, the letter S.
Add another quotation mark and a close parenthesis.
Press enter to finish the function.
To complete the function through all five-thousand words, you could drag down the handle through the entire spreadsheet, but that would take a while.
Instead, double-click on the handle.
The rest of the words now end in S. Now, repeat the process with another variation you would like to use.
For example, many people add their birth year to the end of a password ...
Use your own birth year or another year that’s meaningful to you.
Concatenate also enables you to add something to the beginning of a word.
Start your function with equals concatenate, but this time add the variation in quotation marks first -- here, it is a number that is meaningful.
Add a comma, and A one, then complete the function.
Sometimes, people add an exclamation point to the end of a word when they need to include a symbol in their password.
Continue adding variations to the beginning or ending of the words ...
Until you have five columns of new passwords, with at least one column varying the beginning of the words.
As you can see, it takes very little time and effort to create an extensive list of combinations that could be someone’s password.
And hackers use programs that are much faster than what you did in this lesson -- they have many millions of words and possible variations.
Now, move on to the next video to run a dictionary attack on the passwords you created to test their strength.
Now, it’s your turn: Use five concatenate functions to vary the beginnings and ends of words in the list.
- Use five concatenate functions to the vary the beginnings and ends of words in the list.