What is an OTP bot?

One-time passwords (OTPs) may not be as secure as they seem, as the proliferation of OTP schemes has cast a shadow over what should be an important security feature. Given their popularity, the increasing proliferation of OTP bots targeting these systems is even more worrying. Here's everything you need to know about OTP bots so you can stay safe from this threat.

What is one-time password (OTP)?

To understand OTP bots, you first need to know what OTP is. As its name suggests, One-time password is a temporary login code you receive after entering other authentication information like your email address and password. They usually only last 30 to 60 seconds before no longer granting access to the account.

The idea here is to prevent people who might have stolen, guessed, or performed a Brute Force attack from getting 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 passwords is relatively easy, but it's unlikely that criminals will get your password and your phone.

How does OTP bot work?

OTPs have become so popular that some phones now automatically delete these verification codes to clean up inboxes. While that means your online accounts are safer than ever, it makes the OTP system itself 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 code. To do that, they often impersonate the service the user is trying to log into. Imagine a cybercriminal trying to log into your online banking account. Once they enter your credentials, the bot will text, email or call you, pretending to be the bank asking for your code.

Because the bot acts immediately, that request will arrive at the same time as the message carrying your code, so this doesn't seem suspicious. You could then reply with the OTP, accidentally sending it to hackers, who can then use it to access your account.

Another way for OTP bots to work is to intercept the OTP message before it reaches you. When successful, this method may cause fewer alarms but is more difficult to implement. There's a reason why Verizon's annual Data Breach Investigations Report found that most attacks involve a human element - humans are often the weakest link.

How to protect against OTP bots

OTP bot attacks are alarming, but you can prevent them. Remember to always verify before trusting anything and don't respond to suspicious requests.

If possible, you should enable anti-phishing MFA features, although these are not yet common. Anti-phishing 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 because the real service won't use them.

Even if that type of MFA is not available, you can still enable other identification factors besides OTP. Biometrics like facial recognition or fingerprint scanning are a great option. While it is possible to bypass biometric authentication, it is highly technical and not as common as password-centric attacks, so these factors are still more secure than OTP.

Finally, always be on the lookout for suspicious activity. If you receive a notification about a login attempt that you don't remember or are sure was not yours, contact the service in question immediately. Likewise, change your passwords and contact the company if you notice activity on any accounts you don't remember. Acting quickly is key to stopping attacks before they do much damage.

Learning about OTP bots is the first step to protecting yourself from them. When you know what to look out for, you'll understand how to stay safe.

Remember that no security system is 100% reliable. OTP and other MFA methods are an important part of ensuring good cybersecurity, but they are not perfect. Therefore, you should always approach things with caution and keep an eye out for suspicious activity.

Lesley Montoya

Update 04 November 2023