NEW YORK (CNN/Money) - Investors beware: If a wily female, apparently believing she's calling someone else, leaves a message with you advising of a hot stock tip, walk away. According to the Securities and Exchange Commission, it's a scam.

In a press release Thursday morning, the SEC said voice mail messages are appearing on home answering machines from coast to coast saying that the stock price of certain small, thinly traded companies will soon shoot up.

The breezy, intimate messages sound as if a female caller mistakenly believes she has dialed a girlfriend and is confiding inside information she has learned from "that hot stock exchange guy I'm dating." (to hear audio of message, click here)

The SEC believes the scam is part of a "pump and dump" scheme, where the perpetrators get as many people to invest in a chosen stock then dump the shares they own, making a tidy profit themselves and leaving duped investors with a loss.

Apparently, the scheme is working. The SEC said many of the targeted companies have seen a rise, then a quick fall in the price of their shares as soon as the con artists stop touting the stock.

To avoid getting fleeced, the SEC is offering this advice: "Investors should never buy stocks on the basis of 'hot' tips from strangers" said SEC Investor Education Director Susan Wyderko.

The SEC is asking investors who receive these kinds of calls to let them know the company being touted, the exact date and time the call was received, the number called, and the number from which the call was made, if available. E-mail the information to Enforcement@sec.gov, or call the SEC at 1-800-SEC-0330.

The SEC's investor alert can be seen here.