Stay one step ahead of the fraudsters with our series of articles giving you the lowdown on the scams they use to trick people out of their hard-earned cash - and how to avoid being taken in by them.
This week, we take a closer look at a frighteningly effective computer virus that has just been discovered.
How does it work?
This complex spying virus, called Regin, is designed to collect information by capturing screenshots, stealing passwords and even recovering deleted files.
Computer security giant Symantec, which discovered the bug, believes it must have been created by a government about eight years ago and is hailing it as one of the most sophisticated pieces of malicious software ever used.
"Regin displays a degree of technical competence rarely seen," the company said.
How can I avoid being caught out?
At the moment, the general consensus is that Regin is being used by a national government, rather than gangs of cyber criminals.
However, there are plenty of other sophisticated viruses out there. So to protect yourself from fraud, it is sensible to keep your operating systems, firewalls and antivirus software up to date to make life more difficult for anyone trying to spy on you.
Not using the same password for all your accounts, and changing your passwords on a regular basis, can also help to protect you when cyber criminals strike.
I've been defrauded. What should I do?
Symantec believes that Regin has mostly been used to spy on government organisations, businesses and individuals in Russia and Saudi Arabia, although cases have also been identified in Belgium, Austria and Ireland.
Its sophistication makes Regin very hard to spot. But if you think your computer has been infected by a virus of any kind, it's definitely worth running an online virus scanner such as the Microsoft Safety Scanner.
It is also important to notify any relevant organisations - such as your bank - that you think there has been an online security breach, and to change your passwords and login details to prevent hackers accessing your accounts.