The original fraud alert from August with details on the scheme and these companies can be read HERE!
As always, the best advice to avoid these types of scams is to never pay any type of upfront fee to sell or rent a timeshare property. In a traditional real estate transaction, the buyer is the party who provides a good faith deposit to open an escrow account with a legitimate closing company. Any seller escrow, transaction, or broker fees are then deducted from their proceeds at closing. The timeshare sale process should be very similar to a residential sale process.
If you receive an offer and it requires you to submit a payment to a closing company you do not recognize, make sure you research the validity of the company in question- or simply refuse to do business until another closing agent is chosen. There are numerous well known title companies that offer escrow service for timeshare transactions, such as First American Title Company.