Cookie Theft: How to Keep Cybercriminals Out of Your Accounts | McAfee Blog

Chocolate chip, oatmeal raisin, snickerdoodle: Cybercriminals have a sweet tooth just like you. But their favorite type of cookie is of the browser variety.

Browser cookies – often just referred to as cookies – track your comings and goings on websites. And when a cyber thief gets their mitts on your browser cookies, it can open all kinds of doors into your online accounts.

The first step to protecting your devices and online privacy from criminals is to understand their schemes. Here are the key terms you need to know about cookie theft plus how to keep malicious software off your devices.

Key Cookie Theft Terms You Should Know

Cookie theft can happen to anyone. Knowing the basics of this cyberscheme may help you better protect your online life:

• Browser cookie. A small collection of data your internet browser stores every time you visit a website. When your browser stores this data, it makes it quicker for you to log back into a website or for a website to customize its suggestions for you the next time you visit.
• Cache. Like a mouse scurrying away a pile of sweet treats, your device hoards – or caches – all the cookies you gather from websites you visit. Your cache of cookies will grow continually until you clear it out. If your cache grows too large, it could slow down your device, affect performance, or tax your battery power.
• Multifactor authentication. MFA is a way to log in to an online account that requires additional forms of identification beyond a username and password. It could require biometric identification (like a face or fingerprint scan), a security question, or a one-time code.

How and Why Do Criminals Steal Browser Cookies?

Cookies thieves are generally motivated by the financial gains of breaking into people’s online accounts. Banking, social media, and online shopping accounts are full of valuable personal and financial details that a cybercriminal can either sell on the dark web or use to impersonate you and steal your identity.

Malware is generally the vehicle cybercriminals use to steal cookies. Once the malicious software gets onto a device, the malware is trained to copy a new cookie’s data and send it to the cybercriminal. Then, from their own machine, the cybercriminal can input that data and start a new session with the target’s stolen data.

There was a stretch of a few years where cookie thieves targeted high-profile YouTube influencers with malware spread through fake collaboration deals and crypto scams. The criminals’ goal was to steal cookies to sneak into the backend of the YouTube accounts to change passwords, recovery emails and phone numbers, and bypass two-factor authentication to lock the influencers out of their accounts.¹

But you don’t have to have a valuable social media account to draw the eye of a cybercriminal. “Operation Cookie Monster” dismantled an online forum that sold stolen login information for millions of online accounts gained through cookie theft.²

Best Practices for Secure Browsing

To keep your internet cookies out of the hands of criminals, it’s essential to practice safe browsing habits. These four tips will go a long way toward keeping your accounts out of the reach of cookie thieves and your devices free from malicious software.

1. Set up MFA. MFA may seem like it’ll slow down your login process, but really, the extra seconds it takes are well worth it. Most people have their phone within arm’s reach throughout the day, so a texted, emailed, or authentication app-generated code is easy enough to access. Just remember that a reputable company will never ask you for one-time codes, so these codes are for your eyes only. MFA makes it extremely difficult for a criminal to log into your accounts, even when they have your password and username. Without the unique code, a bad actor is locked out.
2. Watch out for phishing attempts and risky websites. Cookie-stealing malware often hops onto innocent devices through either phishing lures or through visiting untrustworthy sites. Make sure to carefully read every text, email, and social media direct message. With the help of AI content generation tools like ChatGPT, phishers’ messages are more believable than they were years ago. Be especially diligent about clicking on links that may take you to risky sites or download malicious files onto your device.
3. Clear your cache regularly. Make it a habit to clear your cache and browsing history often. This is a great practice to optimize the performance of your device. Plus, in the case that a cybercriminal does install cookie-stealing malware on your device, if you store hardly any cookies on your device, the thief will have little valuable information to pilfer.
4. Use a password manager. While a password manager won’t protect your device from cookie-stealing malware, it will lessen your dependence upon storing valuable cookies. It’s convenient to already have your usernames and passwords auto-populate; however, if your device falls into the wrong hands these shortcuts could spell trouble for your privacy. A password manager is a vault for all your login information for your dozens of online accounts. All you need to do is input one master password, and from there, the password manager will autofill your logins. It’s just as quick and convenient, but infinitely more secure.

Lock Up Your Cookie Jar

McAfee+ is an excellent partner to help you secure your devices and digital life. McAfee+ includes a safe browsing tool to alert you to suspicious websites, a password manager, identity monitoring, and more.

The next time you enjoy a cookie, spare a moment to think of cookies of the digital flavor: clear your cache if you haven’t in awhile, doublecheck your devices and online accounts for suspicious activity, and savor the sweetness of your digital privacy!

¹The Hacker News, “Hackers Stealing Browser Cookies to Hijack High-Profile YouTube Accounts”

²CNN, “‘Operation Cookie Monster:’ FBI seizes popular cybercrime forum used for large-scale identity theft”