Newly redesigned $100 notes lay in stacks at the Bureau of Engraving and Printing on May 20, 2013 in Washington, D.C. The bills have new security features, such as a duplicating portrait of Benjamin Franklin and microprinting added to make the bill more difficult to counterfeit.  View Full Caption Mark Wilson/Getty Images

NEW YORK CITY — It’s all about the Benjamins. 

An international counterfeiting ring has been pumping millions of dollars in phony $100 bills into New York and other cities in the metropolitan area over the past several years, forcing the Secret Service to step up its operation to shut it down, sources told "On The Inside." 

Federal officials are tracking the mules who smuggle bogus bills into the country and distributing an alert to New York businesses, banks and security industry personnel that teaches how to detect the fake C-notes, a copy of which DNAinfo New York obtained. 

The counterfeit cash appears to have been manufactured on offset printing machines using plates and ink, rather than on more sophisticated copiers, according to Michael Seremetis, the assistant special agent in charge of the New York Secret Service office. 

The loot is produced in bulk and bundled into packages that are smuggled in luggage or carried on planes by couriers who get about 40 cents on the dollar to put the fakes into circulation. 

“The network is similar to that of the narcotics trade,” Seremetis explained. “ It is distributed via a sophisticated network that involves several mules who do the passing of the notes here in the tri-state area.” 

The Secret Service warning says the bills contain a set of five different serial numbers and have two black 7s above the last zero on the lower right-hand corner, above the “100” mark on the back of the bill. 

Although the Super Bowl game is taking place in the New York City area, officials are downplaying any connection between those festivities and the timing of their warning — and insist counterfeiters are not using the big game as a convenient time to pass off their funny money. 

The counterfeit cash frequently turns up in clubs, bars and casinos, officials said.  Department stores over holiday periods are typical targets. 

If you have a phony $100 that is confiscated, you will lose the value of the money but can declare a tax loss at the end of the year, officials said. 

“We are asking the public to let us know if they encounter these bills,” Seremetis said. 

Officials asked anyone with information to call the Secret Service's New Haven office at (203) 865-2449, or the NYPD at 1-800-577-TIPS.  All calls will be kept confidential.