The subject may vary from "Spyware Alert!", "Trojan Detected!", "Virus Detected!", etc. Regardless of the subject, don't be fooled. Instead, click the delete key.
The link from the sample below was removed and changed to red:
Our robot has detected an abnormal activity from your IP adress
on sending e-mails. Probably it is connected with the last epidemic
of a worm which does not have official patches at the moment.
We recommend you to install this patch to remove worm files
and stop email sending, otherwise your account will be blocked.
Customer Support Robot"