There are two types of automated threats that leverage user credentials to target login pages with account takeover.
If your website has a login page, chances are good that it's targeted in account takeover attacks. Nearly all (96%) websites with login pages have bad bots and are hit with account takeover attempts, report researchers from the Distil Networks Research Lab.
Login pages are among the most abused Web pages, a finding from the 2017 Bad Bot report that prompted the research team to analyze the anatomy of account takeover attacks in greater depth. They studied data from 600 domains with login pages and pulled a smaller subset of 100 Web pages, which had the largest data sets of bad bot traffic, to study them further.
Account takeover attempts are intended to test credentials for validity. If they're legitimate, attackers sell the usernames and passwords on the Dark Web or gain account access to pilfer personal or financial information and sell that instead. Alternatively, they could use the account to transfer money, purchase goods or services, or spread disinformation campaigns.
There are two types of account takeover attempts and they occur at about the same frequency, researchers report. Half are volumetric, meaning the bot floods the login page with credentials in an attempt to verify them as soon as possible. These "credential-stuffing" attacks are easy to identify because they're accompanied by a spike in activity: the average credential stuffing attack will involve 35,000 to 50,000 requests and between 500% and 5,000% increase in login page traffic.