Cybersecurity expert Hieu PC guides how to avoid revealing personal information

Buying necessities, medicine... even getting a haircut can put your personal information at risk of being leaked to the "black market".

Personal information is sold on the "black market" - Photo: NVCC

Buying things and getting a haircut are also asked for personal information

Having lost 400,000 VND to a scammer posing as a delivery shipper, Mr. NHH (living in Hanoi ) did not expect to be scammed so convincingly.

There was a phone call to inform him that the package was delivered to his home address during business hours. Because he did not check the information on the app, he still paid through the bank account that the scammer sent via text message. It was only after a while that he realized he had fallen into the trap.

Surprisingly, this guy knows the product information and habits well, which makes it easy to convince the victim to transfer money.

After providing her phone number and date of birth to a store selling household appliances at a fixed price to become a member and receive discount points, Ms. PHT (living in Hanoi) was quickly surrounded by invitations to invest in stocks, lend money, and offer summer vacation bonuses...

From the above incidents, cyber security expert Ngo Minh Hieu advised people to be cautious. When a store asks for personal information such as phone number, full name, date of birth, address, ID number, etc., the buyer must ask the store to clearly explain the purpose of collection. If it is unreasonable, they have the right to refuse and not provide more information.

“Collecting personal information at the counter, if not transparent and secure, is an ‘open door’ for privacy violations. The management system and wifi, if not protected, will also be a loophole for data loss,” Mr. Hieu affirmed.

This is just one of the loopholes that bad guys take advantage of to steal personal information and sell it on the "black market".

Many closed groups on social networks (Facebook, Telegram...), niche websites, even automated chatbots sell customer data: name, phone number, address, income, bank account... Both free and paid packages are available, with a commitment to "warranty" or update data upon request.

According to experts, some information was leaked from organizations such as banks, real estate, airlines, telecommunications... because employees with access rights took advantage of it to exploit and sell the information.

Information thieves also use high-tech methods such as "scraping data" from the system, taking advantage of technical vulnerabilities, and using automated software to collect and put data online for sale.

To serve different needs, data buyers and sellers divide information into packages and sell them at different prices.

Basic information packages (phone number or simple information) are sold at very cheap prices, from 100 VND/data; detailed personal information such as full name, ID card, address, occupation... can cost 10 times higher.

High-quality data packages are for people with large assets (savings, real estate, luxury cars), overseas Vietnamese... can be sold at prices up to 1.5 - 3 million VND for 1,000 people.

Cyber security expert Ngo Minh Hieu - Photo: NVCC

Bad guys impersonate individuals to “launder money”

When possessing personal data (such as phone number, address, ID card number, occupation characteristics...), bad guys can easily create very familiar and convincing scam situations. For example, impersonating a bank employee to announce a winning prize or pretending to be a shipper to confirm an order...

According to Mr. Hieu, “in addition to common fraudulent acts, personal information when exposed can be exploited to open bank accounts, register for credit loans, complete insurance procedures or get quick loans. Impersonate the victim to commit financial fraud or launder money through fake legal entities.

Account hijacking and intrusion into services such as financial accounts such as e-wallets, e-commerce. From here, use the compromised account to try to log in to other services - especially if the user has a habit of using the same password.

To avoid becoming a victim of online fraud, users need to equip themselves with prevention knowledge, always update their systems, browsers, anti-virus software and enable automatic updates to protect their devices.

Set strong, unique passwords for each account and enable two-factor authentication (2FA). Monitor your cards/bank accounts regularly, enable transaction alerts, and take immediate action if you spot anything unusual.

In particular, use a secondary SIM or SIM PIN, when you need to give your phone number, consider using a secondary SIM or setting a PIN to increase security. From here, monitor strange activities related to the SIM number, if there are signs such as loss of signal, SMS not arriving, contact the network operator immediately.

Be vigilant against new scams, slow down, react selectively, report and share with the community.

In case the victim accidentally transfers money to scammers, they need to quickly notify the bank or authorities for support.

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Source: https://tuoitre.vn/chuyen-gia-an-ninh-mang-hieu-pc-chi-dan-cach-tranh-lo-thong-tin-ca-nhan-20250816162921845.htm