- A new variant of the Frethem worm family has been on the rise in the wild during the late hours of June 11. E-mails sent by Frethem have the subject Re: Your Password! and the attachment decrypt-password.exe and password.txt. E-mails constructed by Frethem have a MIME header that is designed to exploit a known vulnerability to automatically execute the malicious attachment when the e-mail is ...www.idefense.com