One-time passwords (OTPs) may not be as secure as they seem, as a rise in OTP bots casts a dark shadow over what should be an important security feature. Given how common they are, the growing prevalence of OTP bots targeting these systems is all the more concerning. Here’s everything you need to know about them so you can stay safe from this threat.
What Are One-Time Passwords?
To understand OTP bots, you first need to understand OTPs themselves. As the name suggests, a one-time password is a temporary login code you get after entering other credentials like your email address and password. They typically last just 30 to 60 seconds before they’ll no longer grant access to an account.
The idea here is to stop people who might’ve stolen, guessed, or brute-forced your password. By sending a one-time code via call, text, or dedicated mobile app, the service ensures the person logging in also has access to a trusted device. Stealing a password is relatively easy, but it’s not likely a criminal has your password and your phone.
How Do OTP Bots Work?
OTPs have become so common that some phones now automatically delete these verification codes clear the inbox. While that should mean your online accounts are more secure than ever, it’s made OTP systems themselves a target for cybercriminals. OTP bots target these systems in one of two ways.
The first and most common way OTP bots work is by tricking users into revealing their one-time codes. To do that, they often impersonate the service they’re trying to log into. Imagine a cybercriminal is attempting to log into your online banking account. When they enter your credentials, a bot will text, email, or call you, pretending to be the bank asking for your code.
Because bots act immediately, that request should come at the same time as the message carrying your code, so it may not seem suspicious. You may then reply with the OTP, accidentally sending it to the hacker, who can then use it to access your account.
The other way OTP bots work is by intercepting the OTP message before it reaches you. When successful, this method may be less likely to raise alarms, but it’s harder to pull off. There’s a reason why Verizon’s annual Data Breach Investigation Report found that most attacks involve a human element—people are often the weakest link.
How to Defend Against OTP Bots
OTP bot attacks are alarming, but you can stop them. Remember to always verify before trusting anything, and err on the side of not responding to unsolicited requests.
In this context, that means checking with your bank or other service to see if they ever reach out about OTPs without action on your part. Most don’t, so it’s generally best not to answer an OTP request if you didn’t try to log into anything.
If available, you should enable phishing-resistant MFA features, though these aren’t common yet. Phishing-resistant MFA removes the human element from the equation, instead using cryptography and device authentication to verify login attempts. That way, you’ll know that any OTP requests are scams, as the real service won’t use them.
Even where that kind of MFA isn’t available, you may be able to turn on identification factors other than OTPs. Biometrics like facial recognition or fingerprint scans are a great option. While it is possible to bypass biometric authentication, it’s highly technical and not as common as password-focused attacks, so these factors are still safer than OTPs.
Finally, always be on the lookout for suspicious activity. If you get a notice of a login attempt you don’t remember or know wasn’t you, contact the service in question immediately. Similarly, change your passwords and contact the company if you notice activity on any accounts you don’t remember. Acting fast is the key to stopping attacks before they cause much damage.
Awareness Is the First Step Toward Security
Learning about OTP bots is the first step in protecting against them. When you know what to watch out for, you’ll understand how to stay safe.
Remember that no security system is 100 percent reliable. OTPs and other MFA methods are a crucial part of good cybersecurity, but they’re not perfect. Consequently, you should always approach things with caution and watch for suspicious activity.