The trojan, a variant of PWSteal.Bancos.Q, has so far affected only Brazilian banking sites, but is likely to spread, according to PC Tools' malware research center which discovered the trojan Wednesday.

The trojan monitors users Internet usage, collects all login information entered by users on financial Web sites via mouseclicks and keystrokes and then sends that information back to the author of the trojan.

"Many online banking sites have instituted the use of virtual keyboards in an effort to avoid keylogger infections. With this new variant of the keylogger threat, however, PC Tools cautions this security measure may not be sufficient," said PC Tools spokesperson Magida Ezzat. More information about the threat can be found at: http://www.pctools.com/mrc/