A new version of a notorious virus is being held responsible for stealing banking details from many customers, a security firm has said.
M86 Security experts believe criminals in eastern Europe have so far taken around £675,000 from current accounts by using the Zeus virus.
The threat was uncovered after the firm looked into the criminals' command server, where details of all the transactions were logged.
Customers may have unwittingly enabled the virus to infiltrate their accounts by clicking on a link to an illegitimate website, which then locates their passwords after they log into their online banking services.
Social media platforms are increasingly being used by cybercriminals to effectively spread malware, according to a report published by content security solutions and forensics malware tools provider Norman.
It noted that Twitter and Facebook have become the primary targets, as opposed to PC-based systems used in the past.
By Ruth Bradshaw