Interesting post, but you've chosen to hide it where no-one is ever going to see it.
Look on the right hand side of the forum page under 'Actions' and select 'Move Thread'
On the next page, select 'All Communities' and from the drop-down list select - let's see, where would be best for this - try it in
It looks as if the PCs that sent you the spam emails may have been the ones infected with a virus. I'd tell the senders to scan their PCs at once, urgently. They may have been hijacked by a botnet, which would use them to churn out junk like this.
McAfee SiteAdvisor appears to have only one site called "xhealthc.com", and that is rated Yellow ("Caution"). One of the site reviewers has identified it as a spamming site.
Both the URLs that you provide in your post appear to have vanished. UTrace does not have a record of either of them, nor of the generic derivative "xhealthc.com". So I think they were set up to make a quick buck and then closed down again - or were closed down.
It probably means whomever sent it out could be infected although there are some types of malware that spoof the sending address so sometimes these things are difficult to track down. Or it could simply be spam which comes in all shapes, sizes and varieties.
In addition to regular security software I always recommend people carry at least 1, preferably 2 anti-malware applications in addition to antivirus/firewall. Just make sure they are always updated and never use any that incorporate antivirus as well, as those will clash with your established antivirus.
Some are mentioned HERE.