How do you use Wi-Fi when you travel abroad? Many people connect to "Free Airport WiFi" while waiting for their luggage. You might connect to free Wi-Fi at a cafe to upload to Instagram, or search for things on the subway. It's easy to use public Wi-Fi without much thought.
I'm quite wary of public Wi-Fi, so I only use hotel Wi-Fi, and even then, mostly just for searching. I buy plenty of eSIM data and rarely connect to Wi-Fi when I'm out and about during my travels. At first, it was just a vague feeling of unease, but it turns out that was the right choice. Free Wi-Fi abroad is a genuinely risky area, more than you might think.
If you usually connect to Wi-Fi without much thought, take a moment to read this.
3 Real Dangers of Free Wi-Fi Abroad
1. Evil Twin → Fake Wi-Fi pretending to be real
This is the most common trick. Hackers set up fake Wi-Fi networks near airports or cafes with names identical to legitimate ones. For example, if the real Wi-Fi is "Free_Airport_WiFi," the hacker might set up "Free Airport WiFi." The difference can be as subtle as one character, or even the exact same name, making it almost impossible to distinguish.
If a user connects to it, all their data passes through the hacker's equipment before going to the internet. KakaoTalk messages, Instagram logins, emails, and even credit card numbers can all be intercepted. This is called a "Man-in-the-Middle (MITM) attack." This is what it's called.
2. Even with real Wi-Fi, eavesdropping is possible within the same network
This is the truly scary part. Even legitimate, official free Wi-Fi isn't safe. If someone else connected to the same Wi-Fi decides to, they can snoop on data within the same network.
Is there someone next to you at a cafe with their laptop open? That person could be a hacker. If you're on the same Wi-Fi, they can see all the data leaving your phone. Of course, communication encrypted with HTTPS (the padlock icon in your browser) is safe, but not all apps use it.
3. Malware automatically installed just by connecting
This is a more sophisticated method. Some fake Wi-Fi networks automatically install malware on your phone the moment you connect. You might think the internet isn't working and switch to another Wi-Fi, but the malicious app has already been installed on your phone and is stealing information in the background.
Malware installed this way can steal your phone usage information, keyboard input, and even screen captures.
Therefore, 5 Things You Should Absolutely Never Do
If you're connected to free Wi-Fi abroad, absolutely do not do these 5 things.
- Logging into banking apps → Risk of exposing all account information
- Logging into KakaoTalk on a new device → Kakao account completely hijacked
- Entering credit card information → Hotel reservations, shopping payments, etc.
- Logging into email/SNS → If your account is hijacked, secondary damage from impersonation
- Cloud synchronization → All photos/contacts exposed
Searching or looking at maps generally poses no major risk, but logins and payments must always be done with mobile data (eSIM or roaming). Additionally, I frequently use incognito mode.
Is Hotel Wi-Fi Still Okay?
I do use hotel Wi-Fi. There are two reasons.
It has a password — Hotel Wi-Fi that requires a room number or a separate password to connect is much safer than public Wi-Fi. Because not just anyone can access it.
It's managed by the hotel — It's a hotel, so they pay some attention to security. It's different from cafes or airports.
However, hotel Wi-Fi is not 100% safe. While extremely rare, a hacker among other hotel guests could pose a threat. That's why I only use hotel Wi-Fi for searching or maps. I don't open banking apps or Kakao Pay even on hotel Wi-Fi. I always use eSIM mobile data for those.
This is how I usually do it
When I go abroad, I always buy plenty of eSIM data. I get a bit extra just in case I run out. It might seem expensive at first, but since it solves all security threats, I consider it a truly cost-effective investment.
My usual pattern:
- When at the hotel: Only use hotel Wi-Fi for searching, maps, and YouTube.
- When outside: Use eSIM data for everything (maps, payments, SNS, all of it).
- Logins/Payments: Always use eSIM data (even on hotel Wi-Fi).
Unexpected Danger — Airport USB Charging Ports
Additionally, I'll share this with you. Besides Wi-Fi, airport USB charging ports are also dangerous.They are.
This is called "Juice Jacking," where hackers pre-install devices in USB ports at airports or public places and steal phone information while you charge. The Korea Internet & Security Agency has even issued warnings about this.
Safe methods:
- Use your own charger + wall outlet (no USB ports)
- Carry a portable charger
- If only USB ports are available, use a "data-blocking USB adapter"
I always carry a portable charger because I can't charge on the plane. I use it upon arrival at the airport and only charge with a wall outlet once I get to the hotel.
Finally,
to summarize, free Wi-Fi abroad is truly dangerous.
Evil Twin, Man-in-the-Middle attacks, and automatic malware installation— all three threats are present. Searching is fine, but you should absolutely never log in or make payments.
The safest method is ultimately to use mobile data with eSIM or roaming. Many people hesitate when they see the price of eSIM data, but it's a truly small cost compared to having your credit card information stolen.
Using hotel Wi-Fi only for searching and relying on eSIM data when outside seems to be the most realistic way to protect your information. Never forget that if you just connect to Wi-Fi carelessly, you're inviting hacking risks!