Tesco shoppers are being urged to check their Clubcard account statements as soon as possible after a report of fraudulent activity.
Tesco has found that fraudsters have been abusing the system to steal Clubcard point vouchers.
The hack seems to be hitting customers trying to use Clubcard points to get vouchers with Hotel.com, reports MEN.
It is believed groups were stealing codes to sell on to others online to use. Not only does this affect hotels.com but also Clubcard holders as the codes were single-use only meaning Tesco customers are not able to use any which were deciphered by hackers.
Tesco has now pulled the voucher from its website.
All of the Clubcard customers who have been affected should have now received replacement vouchers or had Clubcard points reimbursed.
Any shoppers who suspect they have codes that have been used should contact the Clubcard support team if they’ve not already been contacted.
Cyber security group CyberNews, which discovered the scam in March of this year, says: “In the current economic climate people are looking for ways to save money, so businesses need to stay vigilant to prevent fraud.
“We’d recommend using longer, less predictable discount codes with more characters which make it harder for cybercriminals to predict, as well as implementing a limit on attempts for an incorrect entry to prevent brute force attacks of this nature.”