Bing cashback is a search marketing program that provides online shoppers with cash rebate credit for purchases made through use of Microsoft's Bing search engine. It is a cost-per-acquisition program that allows merchants to specify the amount of promotional funds paid to Microsoft as a sales commission. Microsoft, which operates the program to promote Bing, then passes 100% of the commission to shoppers.
Bing users can earn up to $2,500 annually this way. A 60-day waiting period is required prior to disbursement.
To participate, merchants have the option of using one of two reporting mechanisms, pixel tracking or batch feed. The pixel tracking method isn't as reliable but allows cashback credits to appear immediately in customers' accounts rather than a day after the purchase.
In a blog post last Wednesday, Meghani outlined what he described as "an obvious flaw" in the pixel tracking implementation.
"Anyone can simulate the tracking pixel requests and post fake transactions to Bing," he wrote. "I'm not going to explain exactly how to generate the fake requests so that they actually post, but it's not complicated."
Meghani said that Bing didn't appear to be able to detect fake transactions immediately. He said that he has never bought anything using Bing cashback. Nonetheless, he said that his account showed a balance of $2080.06, the rebate total for two fake $1 orders placed in January and fake orders amounting to $104,000 in October.
Meghani also pointed out that Microsoft's Bing cashback implementation has another security flaw, relying on order IDs in a predictable series. The flaw could allow a malicious user to deny cashback rebates to legitimate users by using up available order ID numbers.
Meghani did not immediately respond to a request for comment.
Following receipt of a cease-and-desist letter from Microsoft's legal representatives, Meghani on Saturday said in a blog post that he had complied with Microsoft's demand and removed the post about Bing's cashback flaw.
He also said that Microsoft has closed his Bing cashback account.
"The purpose of my post was to show an implementation problem, not to encourage defrauding Microsoft," he wrote. "I am surprised they would go through this much trouble to make me take down information that is obvious to anyone reading their documentation. I don't like dealing with lawyers, so I've decided to comply with their request."
A Microsoft representative did not respond to a request for comment.