Temporary phone numbers: a fight for security?
What are temporary phone numbers used for
We are users, and we usually want everything at once. First, we want two-factor authentication to protect our accounts, and then we want convenient email and SMS alerts. Then we're looking for privacy and trying to keep our phones and emails safe from spam.
As a result of this contradiction, services where you can get temporary mailboxes or virtual phone numbers have become popular.
The latter have attracted the interest of analysts. We've been monitoring activity on such services for some time, analyzing what people use temporary numbers for, and whether it's even a safe idea. We're sharing the results in this article.
What are temporary phone numbers used for
So, let's begin. The requests "temporary number", "phone number online", "free sms reception" and the like in a search pop up a lot of services, paid and free, like Canada virtual number.
Then you can "rent" a number and indicate it at the place of requirement (when registering somewhere, placing an order, etc.). A chat room is available for each number and displays incoming SMS in real time.
More than a temporary code
Most messages to temporary numbers are confirmation codes. It would seem that who needs my confirmation code? The code is, indeed, useless. However, the message also shows the resource to which the phone number has been linked.
This means that an attacker could try to access the account by clicking "forgot password". Many resources allow you to change your password and send an SMS with a confirmation code to the same number.
There are a variety of options for further developments: by logging into the account, you can see confidential information (such as the delivery address of the parcel, the details of the linked bank card, etc.). Or you can cancel a purchase. Or spend already accumulated bonus points. Either way, it's pretty frustrating.
By the way, some resources do not just send a confirmation code via text message, but the account password itself. Again, an intruder can steal the account if they change the password to a new one.
We advise you to change the passwords sent by text message to your own in your personal account, even if you use your real phone number
Stakes are growing
The practice varies, but admittedly we were still surprised to find that Hong Kong virtual number were often used for serious things: paperwork, shopping and banking.
Let's start with prepaid purchases from online shops. The most innocuous consequence is that the customer may miss further messages about the status of the order. In addition, sometimes the couriers call the numbers listed to clarify the location or to agree on a delivery time, which would be difficult in this case. But the main risk is that the already-paid purchase will be picked up before the customer does.
To sum up
So, how scary is everything we've discovered? It depends on who is using the number and for what purpose. Mostly they are not used for the noblest of purposes.
Like registering bots in huge numbers to get likes. For small scams - to get a promo code/subscription for a new registration, and for more serious scams - to link someone else's bonus card to your account and spend bonus points.
However, virtual numbers are also being "rented" by ordinary users for their own quite innocent purposes. The number of phone number database leaks is dismal, and the ability to reissue a SIM card without the owner's knowledge is also long-standing news.
So the reluctance to reveal your real phone number is understandable and such services can be handy. Register with them if you are not afraid of losing your account or revealing important information.
Otherwise it's safer to use your real phone number. For example, when registering in messengers and social networks. Some email services and messengers identify a temporary number as unreliable and block it, while others easily give access to an already registered account.
So any resources that store personal information about you are not the best place to use publicly available numbers. Mobile banking should also be tied to a real phone number.
We realise that most people who use these services are not aware of all the possible consequences. We hope that our material will make you think about them and consciously use either your real or "rented" contact details.