In late October, SecureMac discovered a new trojan that affected users of Mac OS X. On Thursday, the company posted a warning that a new variant of the trojan has been discovered.

[ad#Google Adsense 300×250 in story]The new variant was discovered by security firm ESET. The original trojan attempted to trick users into installing the software, but the servers hosting the new variant appear to be hosting updated code for the malware, according to SecureMac.

The servers distributing the updated malware also appear to contain keystroke logs from infected machines, including usernames and passwords, the company said.

Microsoft has also documented the trojan for both Mac and Windows, rating the threat level for both operating systems as severe. SecureMac rates the security risk of the malware as being critical.

Only Intego has rated the threat level as minimal, contradicting Microsoft, SecureMac and ESET’s interpretation of the malware’s threat to users.

SecureMac released a free tool to detect and remove the malware. It is available for download from the company’s website. Instructions to manually remove the malware are also available from SecureMac.