America Online is being invaded by a stampede of Trojan horse programs that can steal a user's password.
Users have been advised by AOL and the National Computer Security Association (NCSA), which discovered the problem, to be extremely cautious when accessing Emails, particularly ones that claim to enhance security.
The programs, which can arrive as attachments to Emails, pose as innocent executables which are able to escape detection from anti-virus software until they are launched. Once launched the programs can locate the user's password by following keystrokes - a technique known as "sniffing". The sniffed data is then sent back to the hacker via Email.
Currently there isn't a virus detector that can handle a Trojan horse, according to Kevin Street, technical manager of Northern Europe for Symantec, publisher of the Norton Anti-Virus package. He said: "We are working on a solution. Trojan horses can be extremely dangerous. For example, they could be set up to delete files on the hard drive. The only defence is to prevent certain activities on your PC or be very careful about what you download."
Jonathan Bulkeley, UK managing director of AOL, agreed: "The best defence against this type of attack is education. We always tell our users to be extremely careful with their Email. If there is an executable or an attachment, don't download it and never use your password, except when you log on."
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