Similar to email Phishing scams like the Nigerian Prince emails asking individuals for their bank account numbers, these letters aim to trick transportation businesses into providing access to financial information or bank accounts.
According to the Office of the Inspector General, US Department of Transportation, scams like this have been running since at least 2005. The Federal Motor Carrier Safety Administration (FMCSA) has posted an updated alert that there is a new round of similar letters dated September 24, 2012 that has just begun circulating again. According to the FMCSA website:
"Another round of fraudulent USDOT Letters dated September 24, 2012 are being distributed, largely by fax, to motor carrier officials. The letters appear to be from the U.S. Department of Transportation Procurement Office and are signed by a fictitious name Julie Weynel [or Julie Wenzel] - Senior Procurement Officer who is NOT an employee of USDOT.
The letters are an attempt to obtain banking information from the targeted carriers."
You can find a sample of one of the letters on the USDOT website. If you receive a request from the USDOT for any financial or bank release information, make sure to verify the sender before providing information.
Know what to look for: download a sample copy of one of the fraudulent letters at http://www.andreini.com/