d1zoyh6qfvajy7.cloudfront.net
dsms0mj1bbhn4.cloudfront.net
These are injected by a CDN to cache resources; in this case you can read the code to see that it is used by Shareaholic, so it is not the culprit.
As this is happening on your landing page, which doens't even look to be a UBB.threads page, I think its safe to say its not UBB.threads related.
The SWF is probably either a resource from malware on the users local device, or is being requested by 3rd party javascript as an advertisement.
If this is affecting only one user and no one can recreate the issue, chances are that it is an issue with the device in question.
