Web attack extorts by encryption

Hackers encrypt data then demand payment for decryption

Security experts today warned of a newly discovered attack in which hackers encrypt data on a compromised PC and demand payment for the decryption key.

The attacks typically start when a user with an improperly patched version of Internet Explorer visits a web page containing malware that downloads a Trojan.

This encodes all files on the local hard drive, as well as any network drives it can reach, and opens a message such as: 'Decoder costs $2000. Send $2000 to e-gold account. Send message about it and I send program to your email.'

Web monitoring firm Websense said in its twice-yearly report on web security that it first came across attacks of this kind in May, but did not say whether any companies have paid for the decryption tool.

A PDF of the Websense report can be downloaded here.