Malicious software that takes computer data hostage and then demands a ransom are increasing dramatically.
According to anti-virus company Panda Software, the new technique called 'ransomware', that uses programs that prevent people from accessing their own documents, has increased by 30 per cent the last six months.
It first appeared in March with the Zippo.A Trojan horse, which searches for files such as Word documents, databases and spreadsheets, and moves them into password-encrypted ZIP files. Then, it creates another file informing the affected user that they need to pay $300 to recover their data.
Since then, a spate of similar Trojans have been released, including Ransom-A, which appeared in April and asked for $10.99, and Arhiveus.A in May which asked people to buy products from an online drugstore.
"If you are asked for money when you try to open a file, your information has been kidnapped," Panda Software warned.
It advised computer users to have an up-to-date anti-virus programme, to watch out when opening unsolicited email messages and to make frequent back-up copies of important files.
Separately, security experts have warned about a new Trojan horse that claims the recipient's credit card has been charged over £125.
The Trojan, dubbed Dloadr.AMA, arrives in an email that claims to come from a company called Cihost, and has the following subject line: [paycheck 322082] Credit Card Chargeback.
If you run the email attachment called PAYCHECK.ZIP, it unpacks to install a Trojan that will attempt to download further malicious code from the internet.
http://www.pandasoftware.com http://www.sophos.com