A senior McAfee executive has warned Mac users to be diligent in ensuring they don't unwittingly spread viruses and malware to Windows users.

He states that the small threat of malware on Macs has made some Mac users blase about security, warning that this could make Macs potential threats on mixed networks.

"An issue (Macintosh) users need to be aware of is that in some cases they can be a carrier - effectively a Typhoid Mary," said McAfee marketing director Allan Bell.

"You can have infected files on the Mac that do not infect the Mac but at a later date can be transferred to a Windows machine which they can infect. Mac users need to scan for Windows viruses," he explained.

Bell also warns that Macs are more under threat than they have been in the past, and that Boot Camp users running a Windows system on their Mac must take special care.