The bank said it has recently seen an increase in the value of such cases, which can involve a fraudster taking over a victim’s computer and freezing them out of their accounts.
Customers may see adverts online for cryptocurrency investment “opportunities”, or be introduced to them by other social media users, and adverts can appear to be endorsed by celebrities.
After sharing their contact details, victims are then offered “high returns” and they may be put under pressure to invest.
The customer may then be told to download software to support them opening cryptocurrency accounts. The remote access software gives the fraudster full access to the computer.
After the victim has opened cryptocurrency accounts and deposited money, the fraudster takes over and freezes the customer out of their account.
Santander said those affected should tell their bank immediately and if they have downloaded software they should turn off and unplug their computer and not use it until the software has been removed and the computer checked by a technician.
Chris Ainsley, head of fraud control at Santander UK, said: “We’re seeing more and more cases where fraudsters use complex…