Introduction
A combo box combines a list box with a single-line editable textbox. It allows users to enter a custom value into the field or select a value from the list of choices.
Combo lists are a common form of data storage used in brute force attacks and credential stuffing. In addition, combo lists can be manipulated to facilitate targeted phishing attacks, impersonation, business email compromise, and extortion.
What is a Combo List?
A combo list is a text file that contains a list of usernames/email addresses and passwords. These files are typically obtained from multiple breaches and then sold or leaked on the dark web. They can be mighty and used for identity theft, hacking, or other crimes.
In addition, they can be used by automatic brute force tools that test multiple credentials on different accounts or website logins until a match is found. This makes them very effective for credential stuffing attacks, which involve obtaining a user’s credentials and then using them to gain Access to accounts on websites or other services.
Multiple companies help you through this, such as SpyCloud, which helps publish content on this subject in light of the epidemic of password reuse. As increasingly more websites and applications require account creation, people can’t recall the many unique passwords they use between accounts.
Combo lists may contain various data, including cleartext passwords or encrypted hashed passwords. Regardless of the type of information they hold, these lists have one common goal: to provide many stolen usernames and passwords that attackers can use to break into online accounts.
These lists are usually derived from various breaches and may be sold on the dark web, but researchers or breach notification services can also reclaim them. This is especially true when these lists are old and need to be more helpful.
Researchers say this is because threat actors across websites and services can reuse a single combination of user details. As a result, the value of these stolen credentials decreases over time as attackers find other sources to purchase them from.
To get around this, criminals often try to sell them on the black market. This can be very dangerous because if an attacker successfully sells the credentials, they can be reused by a new victim.
Types of Combo Lists
A combo list is a type of list box that lets users select multiple values. Combos can also display a single value or a group of related options. They are also helpful in form fields that require users to enter multiple lines of text or images.
There are several combo lists, and you can use them to add features to your applications. For example, you can use a combo list to display the names of your customers or employees. You can also create a combo list to select a specific cost center for purchase.
You can also use a combo list to display values stored in a table. In this case, you bind the list box or combo box to a Row Source list and set the Control Source property to a field from that table. If you edit the list in the table, Access stores the changes in the underlying area and uses them to display the values in the combo box or list box.
When you bind a combo box to a field in a table, you must set the Bound Column and Column Widths properties to values that correspond to the placement of the columns in the list or combo. In addition, you must specify a number to bind the first column in the list or combo box to the underlying field.
If you set the Limit To List property to No, when the user enters a new entry that is not in the list, the combo box or list box displays a message that explains that it cannot be loaded because there are too many entries to be displayed. You can add access to the list or change the Limit To List value to a different matter.
As people reuse passwords across different websites, criminals can use them to take over accounts. For this reason, creating strong passwords unique to each website and service is essential. In addition to displaying multiple entries, a combo list can be used for password-reset campaigns.
Types of Combo Boxes
Combo boxes are a standard graphical user interface widget (or control). They combine the capabilities of a text box and a list box. They can either display fixed values or connect to existing data. They also can display a drop-down list of choices.
During initialization, combo boxes always display the option — Select One– to prompt the user to select an item in the list. This behavior is similar to the default behavior of all native select> elements on forms and grids.
When the value of a combo box is refilled or moved to another column, the list is refreshed automatically. This feature helps screen reader users, who need to navigate among options to perceive them.
If you want the list in a combo box to update once a value is entered, set the listed property to Yes.
You can also create a custom list of values for a combo box. You can do this at design time or programmatically.
To create a custom list of strings:
- Access the Properties window for the combo box.
- In the AutoCompleteCustomSource field, click the ellipsis button to open the String Collection Editor.
- Enter the lines separated by a hard Return and connect OK.
Once the custom list is created, you can let the combo box use it by setting the AutoCompleteMode property to CustomSource.
Creating Combo Boxes
When creating forms, it can be quicker and easier for users to select a value from a list instead of typing in a single value. This feature also helps ensure that the values entered in a form are appropriate.
Fortunately, Access offers several ways to create combo boxes. These include using a wizard or constructing them yourself.
Before inserting a combo box into a form, you must specify the entries you want to display in the list. This is done in the Combo Box Properties dialog box.
The combo box can be set up to offer a fixed list of items or retrieve entries from any database table. In the latter case, the Access provided to the user originates from a database table and is written to the values table of the form.
Another helpful feature of combo boxes is allowing users to select one entry from the list of items. This feature is unique to the combo box and separates it from other types of lists, including list boxes and menu buttons.
In addition to displaying the selected item in the text box portion of the combo box, a simple combo box can show the caption of any item in the list. This handy feature can be beneficial when a user is selecting values from an extensive inventory and needs to scroll down quickly to see the remaining options.
