That malware cannot affect your Mac in any way. It's probably being included in e-mails from an infected Windows user. You should find out what messages that malware is attached to and alert the individual(s) who keep sending it to you. (Or, if it's attached to spam, just junk the spam.) Note that you shouldn't let most anti-virus software remove malware form e-mail messages, as that can corrupt your mailboxes, among other things. What anti-virus software are you using?
I have found the email that contains the viral attachment. I use MacKeeper on my MacBook Pro and I am completely up to date on my OS. I will trash the email, but I guess as a result of the iCloud sync, it comes back. What I mean by that is if I go in and clean up my gmail mail on My Mac, I can erase maybe 500 email messages and not soon after I trash them, they come right back into my mail box. I am not sure how to permanently delete email messages. My active accounts are clean, but the On My Mac gmail keeps and continues to repopulate all email, even after I trash them. Also, since the Mountain Lion upgrades, I now have an "important" mailbox that mirrors my "all messages" mailbox and I cannot permanently delete those of My Mac gmail box either. Any ideas?
I use MacKeeper on my MacBook Pro
Ack! Get rid of that immediately! MacKeeper's bad news. Plus, it does a really awful job of actually detecting malware. See:
My active accounts are clean, but the On My Mac gmail keeps and continues to repopulate all email, even after I trash them.
If you're seeing messages remaining in GMail's All Mail folder after deleting them, that's normal. GMail keeps all messages in there, even after deletion, unless you manually delete stuff using GMail's web interface. See Hiding GMail’s “All Mail” from Apple Mail.
If you're actually having trouble deleting e-mail from an On My Mac mailbox, there's probably something wrong with your mailboxes.
Using Safari or other browser, log in to your Gmail account and delete the offending messages there.
Gmail makes it a bit tedious to permanently delete messages. This is by design and is not necessarily a bad thing if you are fond of retaining emails, but if you want to permanently eradicate emails for good you need to do it through Gmail's web interface. Find them by using Gmail's "All Mail" folder, and once you have deleted them you have to empty Gmail's Trash as well. Do this recursively until you can no longer find the offending messages.
Also, in Mail Preferences > Accounts, select your Gmail account and then Advanced. Make sure you have selected something other than "Never" for "Permanently erase deleted messages when:" This should prevent the messages from reappearing.
Same for "Sent" and "Junk".
Get rid of MacKeeper too.